Hey Jeremy
That is pretty awesome hobby you got. Can you post the picture of Cartwheel Penny.
As for me i got few hobies my self. They actually all my favorite.
1 Astronomy/Astrophotography
2 Professional Go Kart Racing
http://i179.photobucket.com/albums/w297/csiro/jjj.jpg
3 I got a 1000L Salt water fish tank which is pretty rewarding hobby
http://i179.photobucket.com/albums/w...50408_1700.jpg
4 Martial Arts. I do Ninjitsu. Brown belt.