yeah, me too! Amazon has some books that are buy 3 or 4 (cant remember) get one free for certain books. Also, Amazon seems to have some great prices - the Percy Jackson series is $20 and change and Hugo Cabret is $14.99, which is $10 less than stores. Will keep an eye on this thread, as I am just about ready to pay a chunk to Amazon for books!
In terms of B&N make sure you're searching for coupon codes and printable coupons. I have a membership and they are sending me coupons frequently. Earlier this month (and last month) they put 50% off 1 item coupons on their Facebook page too.
My daughter's teacher has an online code for the scholastic website where you don't need the flyers to come home from school. It's great, you can see all the flyers online and I'm always ordering at random times. They charge my card when it ships and it gets delivered to the classroom a few days later.
We buy a lot of Amazon's 4-for-3 promotion books, and DD doesn't mind used books so I'm constantly searching ebay or the used book listings on Amazon. Now that Borders is gone, I also keep an eye out for Barnes & Noble's coupons.