What is cultural relativism, and is it bad?

In a recent blog, I was called a cultural relativist. This got me to thinking. What the heck is a cultural relativist? Aren't we all culturally relative, depending on our culture? And how is absolute truth related to various cultures? Can absolute truth (i.e. Jesus dies on the cross) survive relative cultural expressions?

For further example: I have heard a mission story in which missionaries entered an unevangelized area where they raised and sacrificed pigs, but had no knowledge of sheep or goats. The missionaries described Jesus as the Lamb of God, but the people did not understand. After spending more time with the tribe, they understood that the people used pigs for their religious sacrifices. The missionaries began to describe Jesus as the "Pig" of God, come to fulfill all their ritual sacrifices that were intended to please the gods. The community understood why Jesus came and listened intently to the full presentation of the Good News about the Pig of God. Many were saved.

Now, this seems like cultural relativism to me, while still affirming and preserving absolute truth. The truth is Jesus came to fulfill sacrificial obligations, whether we describe it as lambs or pigs. I feel a little weird saying Pig of God because of all the other connotations that I have for the term "pig." However, that is my culture, and thus my own limitation, not the Gospel's limitations.

Any thoughts on this topic?