Hm, I'm surprised ThinkGeek has something that actually requires work to build.
I built one of those about three years ago, and I had to order it from a kits place in Canada.
It's basically a PIC that generates a composite video signal. I asked for the source from Velleman, but they refused to give it away (of course.)
You can also just use the Pong-on-a-chip found inside almost every Pong game except the original. Give it some power, and it outputs a video signal.
Pongman was my inspiration, They just condensed it down to the P-O-A-C IC thing. Pongman caused me to buy an Oddessy 4000, Oddessy, Home Pong, and Super Pong. All my Pongs have the Bleeps and Pops of Pong Audio Goodness, which I like. Which Pin on the P-O-A-C is audio?[/quote]