Obligations

Aerin's Cranberry Blog has a great post on the subject of obligation.

Aerin raises good questions: Are you obligated to give a gift to someone who gives a gift to you? Are you obligated to give them a gift that is as expensive as the one you received?

I really like Aerin's take on this subject (and not just because she gives this blog a shout out).

I'd like to hear readers' thoughts on this. How do you deal with the question of obligation in gift exchanges?