Mandolinist Butch Baldassari, who has recently begun offering webcasting video lessons, has just made available 5 video lessons on his website. Four of the five tunes are found in his book/CD 30 Fiddle Tunes for the Mandolin. The book is available through Homespun Tapes. The fifth video, Leather Britches, is not found in the book, so consider it a bonus.
The video clips are in quicktime m4v format (mpeg4), the same format used by the Apple iTunes Music Store for video downloads and podcasts. The file sizes are quite manageable. The clip I downloaded was only 5MB in size. For some reason the file downloaded with .m4v.txt as the extension. Once I removed the .txt it opened and played fine in iTunes. The quality is obviously less than DVD, but good enough to learn from. The clip was short, only one time through the tune (I downloaded Whiskey Before Breakfast). It started with a wide shot and then zoomed in for a close up.
If you have an interest in online instructional video, then go check it out.