A while back I tipped you all to the Live.com (Microsoft) cash back offers on eBay. While still a great deal, they don't always have that offer available.
I was tipped by a friend to try something called PaymentKey.com. Basically they offer the same thing as Live's cash back: you created a free account, click on an eBay link in their web site (after log in) and shop at eBay. You can get a check for your cash backs, but I find it much easier to use my PayPal account.
They also offer similar offers for other stores, some big names once, but I think the eBay option is the best!
Cash backs are paid out after only 15 days, much better than Live's 60. I am very pleased so far! We are talking up to 25 % cash back, that can really add up fast.
It takes a few extra minutes to do, but considering the cash backs are automatic and works without hassle, all for free, why not?
The hardest part about it is to remember to actually click the eBay logo on the Payment Key's web site (logged in) before bidding or buying something on eBay. I really recommend it!