I use a company called All American Travel Club. It cost nothing to join. They rebate me 8% on all air tickets minus $25. This means that if you purchase a $300 or less domestic ticket, you get no rebate. Also because of the $50 maximum commission on domestic tickets, that any ticket over $600 will only net you a $25 rebate check, sent with the ticket. However, if you buy a $1000 international ticket, you will get $80 minus $25 equals $55 back. The other down side to this is you have to do all the arrangements yourself. I use EasySabre and list them as my travel provider, then call the next day to verify that they got my reservation and ask them to issue and mail the tickets with the rebate check. After I have the tickets in hand, I call Delta and get my systemwide upgrade.

JayJ