A reader with an iPod touch was kind enough to set us straight on those episodes of "The Office" and "30 Rock" that NBC is making available for the iPhone and iPod touch via a special mobile site.

Apparently, there are ads, and you don't download complete episodes. Rather, the episodes are broken into chunks that you watch as streams on your iDevice. And each segment has an ad attached to it, either at the beginning or at the end.