This is not a joke. It's funny, but serious.
I've gotten sick of people saying that "everything is relative." If someone says this to you, ask them "Is pain relative?" and then slap them. Pain is pretty freakin real. This is not a refutation of relativity, it is a refutation of what I call impoverished relativity -- the idea that all ideas, and all possible ways of looking at the world are equally true and valid.
I'm also sick of people saying that while some things are relative, other things are absolute. This is pure wishful thinking. The use of absolutes, just as in blind belief, is a sign of mental illness. While choosing to believe in absolutes may hold a narrow mind together for a little while longer, it will lead to many, many mistakes and paradoxes. If a system of thought has absolutes in it, it can always be broken, always be shown to be false.
Since neither of these extremes work, we need something in the middle, an integration. This is the way I see it: There are some things that are very close to absolute, such as the pain example I gave above. A system of thought that did not take pain into account would probably not last very long. But I wouldn't rule it out -- that would smell too much like the way people clung to Euclidean Geometry when the Non-Euclidean version came out. ("well, of course parallel lines never meet!"...."256K is enough for anyone
There are also some things that are close to being completely relative. Truth, (at the risk of getting recursive) is the best example. Whether something is "true" or not depends so much on the context, and so much on your needs and goals, that it comes very close to complete relativity. Even if I say "the sky is blue," the perspective of an astronaut migh change that. (Well, as you get closer to the "sky," it actually starts to get kind of black...) And a Zen master would tell me (at least on Tuesdays) that it was not the sky that was blue, but my mind that was blue.
This is the only sane way I can think of to look at it: Relativity and Absoluteness are a scale, the perfect extremes of which are never achieved. And the scales nest inside of scales -- depending on your perpective on perspective, different things can be relative or absolute in different perspectives. Confused? Don't worry -- it's all relative.