This site has collected links to a lot of the Stephen Colbert Green Screen Challenge videos. This ipod spoof, (not featured on the above site), is also really good.

For more information on Stephen Colbert, you can check out his Wikipedia entries, here, here, here and here (incidentally, this last entry is twice as long as the entry for France).

The AP also recently ran a story on Colbert’s rising viral video stardom, you can find it here.