My only question for this is:
What is your Batch Number?
ME <----coming straight from experience (unfortunate Brick on my phone)
You sound like you are stuck on Recovery/ Download. You are in a much better spot than the post i quoted above you. Just as Opcow said, i would use this link:
to flash to stock 2.1. DO NOT USE the ODIN One click!!! If you do, and lets say you unfortunately brick your phone ("what if") then you will end up like the guy above with "phone ! pc" screen.
EDIT: @ linggo: btw....if your Batch Number is 1008, then the only way is to either take it back to At&t (hope for a miracle) or send it in to Samsung (takes 3-5 business days).
1) remove back cover
2) remove battery
3) look under Serial Number/ you will see your batch # (ex: 1006/ 1007/ 1008/ 1009)