Yes, I fully understand I have a serious problem here. Adding stickers to my helmet has become like crack cocaine, it’s addictive. My latest acquisition is the best yet though, a big ol’ tux (available here).
The downside is many people will look at me with this helmet on and think to themselves, “Dude, that guy’s a geek.” Ironically that’s also the upside to this sticker too. 
So, if you find yourself cruising the streets of Atlanta and you see a big guy on a bike with a linux sticker on his helmet you’ll know it’s me. Honk. At best you’ll get a wave; at worst … well.
