http://sports.espn.go.com/espn/page2/simmons/index The guy is trying to name his cloumn "More Cowbell" Discuss.
I've seen this at Mets games and a couple of other places, as well. I actually saw it on a Maryland license plate the other day, too. It seems to be making the rounds for whatever reason.
I've got a fever, and the only prescription is...more "More Cowbell!" Simmons' column is generally a thing of beauty, and he's been on the Will Ferrell bandwagon from Day 1. I believe he's also particularly partial to the classic line "I drive a DODGE STRATUS! "