[iTunes] movies in iTunes?

[Becca]

A friend just gave me a Sansa Sandisk player, and I've been having fun (for variable definitions of "fun") learning how to use it and playing with it. One of the features it has is video. I don't do much video at all (my daughter has some videos we've downloaded from iTunes) but a friend from another list sent me a .mov file to play with on the Sansa.

And now I'm wondering... will the iPod play only videos downloaded from iTunes, or is there a way to get other file types into iTunes?  does one have to run some sort of converter, or do you just bring the files in the same way you do any other file?

-becca