I'm in the process now of sorting thorugh all the video segments I've got lying around here and uploading them to YouTube, which I will eventually compile into a "farnovision" channel. Let's start with this segment from the Discovery Channel's "Origins" program from 1996, to which I contributed the Farnsworth side of the story:
This piece is notable because it includes some footage of an actual Baird Televisor from the 1920s, as well as an animated demonstration of just how mechanical television worked. It's a pretty good illustration of a doomed technology.
Also, pay close attention when they're talking about Felix the Cat. The grainy, blurry footage that you'll see was actually produced in the RCA laboratory in 1929 -- and serves as graphic evidence that Zworykin and RCA did NOT have a viable camera tube before visiting Farnsworths' San Francisco lab in the spring of 1930.