The guys n gals over at ErrorWear sell exactly what their name says, Errors that you can Wear.  I personally am a Fan of all the geek shirts, hats etc, but of all the geekish swag I have beheld...

Errors seem to be much cooler to wear. I mean, a shirt that says GEEK on it is cool, but it really shows you are more of a Geek if you wear an Error.

  Like a baby with an ugly face, Only mothers.. I mean Geeks could love an Error. Well unless your parents didn't mean to have you, then I guess your parents would technically love an Error, that being you. As long as they don't CTRL-ALT-DELETE you or Reboot and start all over again right? =D

My Favorite has to be the broken image, simple yet geeksweet! Visit ErrorWear at http://www.errorwear.com