How do you sell your books?

[cookderosa]

Silly ADD, I really meant to ask how folks sold their books. I've got textbooks from (recent) PF courses, a couple of CLEP REA study guides, used textbooks that I think could be used for DSST exams, etc. I could donate to the library, take to used book store, etc., but I wondered how (with specifics) you sold your books. Thanks. (I really should be working on my stats.)

Ya know, I've always thought we should have a swap/for-sale folder here. So many of us take the same courses/exams, that it seems silly not to recycle resources!