The iPad is an awesome personal video device. It saved our butts during a cross-country move! Unfortunately for the most part you are stuck playing Apple file formats.
There are apps that play other file formats but almost always require some sort of on the fly conversion.
One option of course is streaming video ala Hulu Plus or NetFlix, another option has arrived in the form of CineXPlayer. It plays Xvid videos with no conversion.
Just like other video players before it, last week's MiTube, CineXPlayer's probably won't be around long. It has seemingly snuck into the App Store under Apple's noses.
So, grab it now!
CineXPlayer lets you play AVI videos encoded with the Xvid codec right onto your iPad, after transferring them via File Sharing in iTunes.
They can be played instantly, without conversion. Now, CineXPlayer did have trouble with a couple of teh video we tried but mostly it worked like a champ.
CineXPlayer free in the iTunes App Store