[Russic]

Less of an iPhone/iPod app and more of a mac app, but ivi ($4 in the mac app store) is a dead-easy video conversion tool. You can do a standard drag and drop for video files and it will apply things like cover art and other metadata, convert it, then drop it in your itunes for easy compatibility. What I like is you can point it at a folder and get it to convert videos automatically on a schedule.

I was using iFlicks for this, and while it's awesome I'm in the beta and things aren't very stable for me. At the moment this is 10x's cheaper and does a lot of the same stuff. Speed is decent (but not like iflicks).

Edit: i should point out that through their website you can get the Pro version ($10) which lets you rip dvd's as well. Kinda wish I'd bought that one, but oh well.