OK, so maybe very few people really believe in moral relativism. After all, you can get to some pretty crazy conclusions from it. So what do the majority of people believe about morals? Besides those that adopt an absolute moral system (ie, from Christianity and other possibly transcendent sources), many people nowadays will adopt something I call evolutionary morals (for lack of a better term).
Those that claim this point of view will often say that this belief system is different from complete moral relativism, in that their morals are grounded in an objective system: the greater good of humanity.
The belief system goes like this (I think). Humans evolved as a societal species. We make relationships with each other, and we make social contracts, etc. These things were selected for as we evolved. Therefore, evolution has preserved in us a natural tendency to do things that promote the good of the human race as a whole.
In this way, morals develop. There are things that are definitely bad for the human race, as a whole, such as killing another human without justification. That's why murder is wrong in almost all societies. In fact, any moral can be defined this way: as long as it's good for society as a whole, then it's morally right. Anything that's bad for society is morally wrong. Thus, an absolute standard exists.
If anyone out there can explain this point of view better, or if you have one that's similar to this but there are important differences, please speak up.