I LOVE open source software like this
I've got a great many videos that I've captured in .wmv but haven't had the time to figure out resolutions, formats and burning them to DVDs, yet.
That's all changed now that Lifehacker has a a great post on Burning almost any video file to a playable DVD using DVD Flick.
I was fascinated by ffmpeg when I first read about it a couple of weeks ago. DVD Flick combines this along with other open source tool to create a nice, easy to use package.