This is the info I got from http://www.sdrawer.com regarding Amazon.com. (And I think the UPromise stuff is for TRU/BRU purchases).
BabyMint 5%
MilesMall 1 point per $3
MyECom 500 points per $
SchoolPop 2.5%
Sklif - 10 points per $, but you have to shop through an Amazon link in the Sklif store
UPromise 2% - restrictions apply - see site for details
There's an offer going on right now at Amazon if you haven't shopped in their Apparel Store yet you can get $25 off a future Amazon order (books, etc.--not toys and other things that aren't 100% "Amazon") for buying $75 worth of apparel. They had a similar one before Christmas for $30 and I just used it to buy DS books for his 2nd birthday. With the free shipping over $25, I got 4 books for $0.61!