But maybe, just maybe, you'd like to know what a phrase means before you use it as an insult. This would be a good idea, because it keeps you from making an ass of yourself when someone comes along who does actually know how 'relativism' modifies 'moral'. Rad Geek to the rescue!
"Moral relativism" does not mean "being lax about taboos that you shouldn’t be lax about"; far less does it mean "drawing a mistaken comparison in ethics". Moral relativism is the doctrine that one and the same action can be both right and wrong at the same time—that is, that questions of moral value can only be answered relative to some frame of reference that can change from one judgment to the next.
And a fine working definition it is! Follow the linky for an amusing anecdote/examples of the proper and improper use of the phrase.
Now, I'm supposed to be our resident philosopher (or some shit like that), so I guess I have to have an opinion on moral relativism. Here's the thing: as many of you know, I'm a big fan of Nietzsche, Kierkegaard, Foucault, and other existentialists and postmodernists, but also Kant. On the one hand, existentialism comes with a pretty hefty helping of relativism; since you're all about autonomy, recognizing that you're judging from your own point of view and using phrases like 'teleological suspension of the ethical', you don't put a lot of stock in universal regulations. On the other hand, Kant has a bunch of books on morality, ethics, and social/political philosophy, and in all of them his starting point is that moral rules are universally binding.
I don't have a systematic way of merging these two very different streams of thought, but I'm inclined to do something like the following: Kant's system provides certain moral laws, which are in fact universally binding. Well, one: the categorical imperative, a maxim of respect for rational agents. But to work out the details, to decide in any particular situation which actions are morally permissible and which are not, that is, to actually apply the categorical imperative, you have to incorporate a lot of background information, which comes from your own perspective on the issue. So it seems entirely possible for two individuals to look at the same situation and come to starkly different conclusions about what actions are right or wrong.
I think you can see this really well in Kant's own work. Not that he condones this sort of analysis; far from it. But, for example, when he condemns any sex outside of (heterosexual) marriage in the harshest language, it's obvious that he's using certain ideas about the metaphysics of sex as grist for the mill of the categorical imperative. Then, with a different metaphysics of sex, the categorical imperative concludes that extra-marital sex is morally permissible.