facebook for bookworms

http://www.goodreads.com/

Great way to see what your friends are reading, get new reading material, and speak your mind about your latest read. Plus you'll be surprised to see how many books you've read when you start rating them.

Also sign up for Borders rewards (it's free!) and they send you coupons every week for books and music.
https://www.bordersrewardsperks.com/default.cfm?uBody=GetPassword&CFID=5979375&CFTOKEN=20cf4f2f94e80c7-8E24D4F1-15C5-FE4A-7AFCB70D7C05EFEC&jsessionid=f0303ea1771ebf0b8b83671e311926579672