Root Return to stock

[Intervenient]

What's the easiest way to do this?

 

[jpeg42]

Depends on what you have done. If you haven't rooted or removed AT&T apps, just do the factory reset built into your phone under Settings->Privacy.

If you have played around quite a bit and want to completely bring everything to "out of the box" condition, then check over at xda-developers Captivate development section for a thread called "[STOCK ROM] Odin3 One-Click Downloader". This is a great way to back out if you messed up your phone.