So the other day I was trying to log out of Twitter (newest version, 3.5) with the new iOS 5, and I couldn't find any log out option. I looked over the internet and nothing. Until I figured it out and I thought I'd make a video to make your lives easier :)
This deletes/logs out your account from your phone, it DOES NOT deactivate your account. You'd have to go to Twitter to do that. I was just too lazy to click delete and then log in again.