The RAM mount for the iPhone works really well to attach your phone to your bike. It is great for all kinds of bikes and holds your phone securely while you ride on-road or off-road.

RAM Mount website: http://www.ram-mount.com/

Specific Products that we like:
http://products.ram-mount.com/rammount/productdetail.aspx?partnumber=RAP-274-1U

http://products.ram-mount.com/rammount/productdetail.aspx?partnumber=RAM-HOL-AP6U

The Belkin armband is a great accessory for running or jogging with your iPhone 3G. It holds your phone securely and keeps moisture from coming into direct contect with
phone. Plug in your headphones, play your favorite playlist and go!

Two of our favorite Belkin armband styles can be found here:

http://catalog.belkin.com/IWCatProductPage.process?Product_Id=456406

http://catalog.belkin.com/IWCatProductPage.process?Product_Id=374788