I have to agree with you.  It just makes the process of cause and effect seem a little more supernatural.  I honestly don't know a whole lot on karma, but my understanding is that your deeds will follow you onto into the next life you inhabit, or something like that.  In some aspects, it's the idea that you're accepting the consequences of your actions, rather than having a higher deity reward or punish you. 

Has anyone ever done any studies on karma, like they've done on prayer?  I'm curious to know.  I'll have to do a little research on that later.

According to Hindu philosophy there are 8.4 million births out of which one is human.When you dont do good deeds in the human birth you go to hell whose conditions are similar to biblical hell and then after punishment you have to again pass through the cycle of 8.4 million births which includes different movable species as well as plants before getting human birth again.

This is explained in Garuda Purana. 

Vandalizing Wikipedia is bad karma...
Doing stupid stuff on Slashdot is usually bad karma (unless it is funny, then it is nothing).

Garuda Purana is directly from the mouth of God Vishnu. God Vishnu told this to his vehicle  Garuda(a small bird,like vulture). Who wrote it down is not known, as a bird was only listening.

In the 4th chapter of Garuda Purana Lord Vishnu, tells what kind of people goes to hell. Garuda Purana is recited at the death of a person and it takes 1 year to reach hell after death.

I am only giving some characterstics:

Those who despise places of pilgrimage, good men, good actions, teachers and Shining Ones; those who disparage the Puraṇas, the Vedas, the Mimasa, the Nyaya and the Vedanta;

The shudra(low caste people) who studies the letter of the Vedas, who drinks the milk of the tawny cow, who wears the sacred thread or consorts with Brahmiṇ(highest caste,born from the mouth of Brahma) women;

Who did not make gifts of black cows to Brahmins, nor perform the ceremonies for those who are in the upper body; having suffered great misery in it, go to the tree standing on its bank.

Those who, self-indulgent, do not worship Shiva, Hari, Surya(Sun), Gaṇesha, the wise, and the good teachers,--these certainly go to hell.

Those who do not feed the Brahmiṇ guests, who have come full of hope to the house, even though food is cooked;--these certainly go to hell.

Being tortured thus, men and women by thousands are baked in dreadful hells until the coming of the deluge.

Having eaten there their undecaying fruits they are born again. By order of Yama they return to the earth and become unmoving and other creatures:

Trees, bushes, plants, creepers, rocks and grasses, these are spoken of as unmoving; enveloped in great delusion,--

Insects, birds, animals and fish;--it is said that there are eighty-four hundred thousands of fates of birth-fates.

BGH, you took the words right out of my mouth. 

It was just an extension on his/her/its initial post.

Unfortunately his initial post wasn't on the mark.  It is talking about Hinduism where as the OP is just talking about one aspect of this, the basic concept of good things happening to good people and vice versa, the OP wasn't touching the rest of Hinduism in the slightest.  It has unfortunately lead this thread off topic. 

The idea of karma, as I see it, is just fine UNTIL it is used as religious fuel.

From what I know, karma as a concept originally came from the desire to quantify social relationships and to explain certain social balance mechanisms (which we know to exist). It would be the same as "How much sympathy do you want?" "12 kilograms, please... would you accept 13 ounces of hatred in exchange?".

http://www.buddhanet.net/e-learning/karma.htm

According to Buddhism, this inequality is due not only to heredity, environment, "nature and nurture", but also to Karma. In other words, it is the result of our own past actions and our own present doings.

Pretty hard to call the bolded part irrational, as long as you remember to consider the entire human population. The fact is, however, that everyone must choose to be "good" on their own, there is no supernatural force guiding the wicked to punishment or the righteous to reward.

Edit:

As for Sumra's posts, reading this might clarify;

http://www.veda.harekrsna.cz/encyclopedia/garuda-purana.htm

Hindu philosophy has changed a lot over the years.  I believe for the worse.

http://www.sacred-texts.com/hin/gpu/index.htm   Says;

Since this was written during the medieval era, it is possible that the writer of this text had contact with Christianity. Earlier Hindu texts do not elaborate about 'hell' and 'heaven,' at least not to this extent, and the subject is completely absent in the oldest texts.

Without having had contact with many Hindu's to discuss their beliefs, I really don't know how literally this is believed by most.  Considering the amount of allegory present in Hindu scripture, it's really hard to say. 

That is exactly what Karma is.  I will admit that my studies into Buddhism have been limited, but most westerner's understanding of a guided process(getting "bad karma" and having something bad happen to you because of it, vice versa) is not at all like what Karma is supposed to be.

Karma is cause and effect.  Belief in rebirth or reincarnation has little to do with Karma, if only because there are no "rules" or "guidelines" or even beliefs about how reincarnation "works".  That is to say, believing that doing good things in this life will cause good things to happen to you in your next(or in any subsequent life), or that it will cause you to reincarnate as a certain kind of creature etc, is an irrational belief and completely baseless.

 If you wish to learn more, I encourage you to read  http://www.buddhanet.net

Monastic lifestyles of Buddhism are the only places where you will find rules and punishments.  The tenets of Buddhism do not state "Thou shalt not", but rather encourage one to say "I choose not to", not because there is a reward or a punishment, but simply because it is right.

There's a lot I could say on the subject, but you're better off reading online and in-fact trying to speak to local Buddhists(if you can find any).  Buddhists are not intolerant of any belief, and will encourage you to learn as much as you can about their beliefs.  They will not be interested in "converting" you to Buddhism, as there is no such thing. 

It may be that past actions refers to past lives, but it also definately refers to the actions of ones current life.  If you do not believe in reincarnation, that does not make the concept of Karma invalid;  If it were, how do you explain simple things like being in a bad mood because you had a bad day at work and causing people around you to also be in a bad mood?

Cause and effect, assuming I've expressed by mood in some perceptible way.

I'll say this as many times as I can;  Karma is not a guided supernatural process.  You don't get good things for being good, and bad things for being bad. 

Then is it still karma, or simply cause and effect without a need for loaded synonym to muck things up?

There is no such word as "hindu" in any of the hindu scriptures. Hindu word is a recent invention and was given by the invaders. In persian it means chor/thief.

Hinduism is based on caste syatem.Thats what all the hindu scriptures glorify.Basically the inhabitants of Indian penisula are Aryans and the original inhabitants were Dravidians who are darker in color. Aryan invasion pushed them towards the southern part of India and also Sri Lanka.

 These Dravidians were made slaves and refered to as low caste people called Dalits.

The entire society is divided into four groups/varnas :

1)Brahmans(highest caste/priestly class, these are the ones who wrote all these scriptures, and it was not allowed for low caste people to read these scriptures, they are born from the mouth of Lord Brahma) 

2)Kshatriyas(ruling class/kings/warriors, born from the chest of Lord Brahma)

3)Vaishyas(business class, who earn their livelihood,born from the thigh of Lord Brahma)

4)Shudras(lowest class/untouchables, whose job is to serve all the above three classes). Now a days they are also known as Dalits.

In order to know how shudra/untouchables should be treated the holy hindu scripture  "Manu Smriti" said to be written by son of Lord Brahma should be read.

 Gandhi, father of Indian Nation gave Dalits more fancy name "Harijans", He was a staunch believer in Caste system and said it is for the betterment of society.

Gautam Buddha was born as Prince Siddartha in a Hindu family, in the second category Kshatriya and was a King. But he gave up everything and left his house.

Buddhism preached equality of all and it was a direct threat to hinduism's caste system. Buddhism was specially embraced by low caste people.

It spread far and wide, but when Shakaracharya became the head priest during ??(i can confirm the date), he massacred thousands of budhhist monks and their monastries, and they were forced to fled India. this is the reason that Buddhism born and flourished in India but now it is found in the neighbouring countries like Japan,Tibet,China.It is usually said that in India you wont find any old statue of Buddha that is not disfigured.

There is somewhat similar cult like Budhhism started by Mahavira known as Jainism.

In the Indian Constitution article 25 states "All jain,buddhists are Hindus".

What do you say about Stepehen Hawkins?

the bhagavad gita is a good entry into 'hindu' metaphysics. when i think of hinduism, i think of it's intellectual history, and its most unifying aspect is not any deity, but of dharma and searching for truth. 

essentially, the gita  outlines dharma ethics. the circumstances and characters,  even who krishna is, are secondary.

the word karma is as innocuous as Newton's third law of motion. It is descriptive, not proscriptive.

I can't say I ever believed in karma (or my conception as a westerner of what that word meant), but I always liked the idea that there was some kind of universal justice. Wishful thinking? Of course. But it's easy to see why some people go from wishing to believing. When you look about you and see bad things happening to good people, and good things coming to bad people it's a bitter pill to swallow. Of course it's just how things are, but it would be nice to believe that things worked out for the best "somehow."
Possibly from my reading of Shogun long ago, in which the term "karma" appears frequently described in context as "fate," I took that to be its meaning generally. Looks like I was mistaken. But since I never accepted the idea of karma as rational in the first place, I don't suppose it matters. .
This life hasn't been all bad, but there have been periods of deep suffering for me, as I suppose there have for most people at some point in their lives.  I haven't been physically hurt, unless you consider obesity and its consequences a kind of physical suffering. Mostly my pain (happily now largely in the past) has come in the form of depression. But even at my lowest point, when I might have welcomed the relief of a view like karma or any other kind of universal justice, I realized that wishing just doesn't make it so. Anyway, if you did accept a karmic "system" you would still have the problem of "god." After all, doesn't a system presuppose a designer of the system? No point in going back to that old canard, especially since it took me so damned long to accept that I was an atheist.

Just a quick factual correction.

Lenin didn't "suddenly" fall sick. He was shot (soviet propaganda liked to add with poisoned bullets, too), and the bullets in his body finished him soon after.