I'm not the only person who thinks so:

  "Clay Shirky looked like Tom Hanks but I didn't ask him about his latest movie role (I hope)."

(http://terranova.blogs.com/terra_nova/2003/11/usercreated_co...)

  "If Shirky ever has a movie made of his life, it’ll have to 
  be Tom Hanks that stars. I think he sounds and looks a lot like Shirky!"

(http://blogs.technet.com/johmar/archive/2008/09/18/web-2-0-e...)

  "Imagine hair on him and Shirky looks, talks and acts exactly like Tom Hanks. Not just similar, but eerily exact."

(http://www.chrisroberson.net/2008/04/cognitive-surplus.html)

  "One thing I’ve definitely gotta say about this guy though is that he sounds 
  and looks a lot like Tom Hanks. Not that there’s anything wrong with that."

(http://www.warrenellis.com/?p=5885#comment-229940)