Thanks for the pics, SalvorHardin, M'Sharak, and Etched. The man loves his hats! Seems a shame to cover up such a nice head of hair.
His friend there definitely looks like Chris Pine, startrekrcks.
I think someone actually has a web site dedicated to Zach's hats. . .I know the one in that picture is called the "Fug Hat" in certain circles, and that it has a blue twin. . . and there was a recent party in New York that both Zach and Chris attended with them BOTH wearing hats. . .
That site has been mentioned in this thread a couple of times, at least. This post
includes the link to the blog; unfortunately, the blog doesn't appear to have been updated in quite a while. I think my "dorky hat picture?" link a few posts up includes a photo from the New York event you mention.