The funniest sock pupped in Silicon Valley is operated by Loren Feldman, the absolutely hilarious comic who runs the cult website 1938 Media.  Feldman's puppet is called Shel and is the spitting image of Shel Israel, an exubertantly vacuous Silicon Valley journalist.  In particular, check out Feldman/Shel's interviews with CNET editor-in-chief Dan Farber, Digg founder Kevin Rose and All Things D impressario Kara Swisher.

Silicon Valley takes itself very seriously. So it's not that hard to make fun of it. But Feldman is really really good.  Expect him to eventually breakthrough from the Internet into mainstream media.