I saw this at Lowes and thought it was pretty cool. I guess it could also be used to air up your tires on the trail. When you buy the regulator it comes with a free tank.
http://www.lowes.com/lowes/lkn?action=productDetail&productId=166441-61735-J-6901-100&lpage=none

http://www.lowes.com/lowes/lkn?action=productDetail&productId=166441-61735-J-6901-100&lpage=none
