An amazing array of videos are out there on sites such as YouTube. While the sound quality is not the greatest, being able to watch the bowing and fingering more than makes up for it.
I have started a list of what I think are interesting, fun videos on my web page, which can be found here.
More will be added, and if you know of a good video, let me know.
When I'm learning a tune, I want to listen to it about a billion times, just to pound it into my thick skull. Usually I don't want to keep hitting the YouTube replay button; I'd like to have it on a CD on repeat or on my computer, in iTunes on repeat. With the Zamzar you can convert a YouTube video into an mp3, or mp4 video, or a wide selection of other options I don't understand. This can then live on your computer or be burned onto a CD.
Certainly I'm not advocating this for copyrighted material, or if the version of the tune is available commercially -- we need to support the artists -- but many of the YouTube videos I see are just regular folks playing traditional tunes. It is a good way to learn.