This is pretty cool. Tree Bicycle has two ringtones for you guys, they recorder the sound of their hub and the sound of it flowing through trails.
“If you’ve ever wanted to have the sound of your Tree hub clicking on your phone, or maybe the sound of it flowing through some trails alert you to your incoming calls. Now you can! We have the Tree Rolling, and Roastin’ ringtones available for Iphones via the Itunes store for Iphone. Just go to the Itunes store on your Iphone and search “Tree Bicycle Company” and take your pick.”