I love this thread by the way.
Just found out you might as well go nuts with these things on everyday purchases.
Get your Wal-Mart giftcertificates online to earn extra miles through portals

Same with Starbucks.
Just searched evrewards.com and I particularly like the 4 ThankYou points per dollar on giftcertificates.com . Stack it up with 3 TY points on your Citi Platinum AMEX and you're getting 7:1. I get about 1.5 cent on them so that's 10.5% off your everyday purchases^