Burn almost any file to DVD, for free
You can use DVDFlick, a free (as in speech and beer) and open source app for windows to burn those video files on your computer to a DVD you can play in your living room. In a few simple steps, here’s how to burn almost any video file on your computer to a playable DVD.
You can find a howto guide here.
Linux users who aren’t afraid of the command line? tovid to the rescue.