I discovered this trackable BTC T-shirt today (5/25/2012) while I was in the area to attend the "The Zombie Horde Flash Mob Event" http://coord.info/GC3JGKV event during GeoWoodstock X weekend.
Thank you for putting this one on yourself for me to discover! It was quite fun meeting people wearing these T-shirts and talking about caching, trackables, or even other random stuff!