I like iMapmyride. It will also upload your progress as your Facebook status if you want it to. I only had a problem with it once. I rode about five miles and it said that I rode 3900 miles.

Has anyone else that uses it had a problem with the GPS? Everytime I load it, just before my ride, it tells me that it can not get a GPS signal and then asks should it continue anyway. Well I sayd "yes" and have no problems. No biggy, just kind of a hokey pain every time.