UPDATE 6-18-08: This deal appears to have dropped from 35% to 10%. eBay currently has a promotion that offers up to 35% back on items purchased through the “Buy it Now” link for eBay auctions displayed on Microsoft Live Search and paid for via Paypal. The trick is you must go in via a special Microsoft Live Search link to be eligible. There are a bunch of terms and conditions and the maximum you can save on any one purchase is $250 - and you’re limited to using the discount a total of three times. To participate you need to locate one of the cash back ads on a Windows Live search - like this one (click on the eBay auction at the top of the page with the “Live Search cashback” icon). Tempted? Take a minute to read through this discussion thread on the deal web site Fatwallet.com for more details.

Link: eBay Cash Back Terms & Conditions
Link: Deal discussion via Fatwallet