I've been using the iMap My Ride application periodically for the last few years. Seems to work well and the software interface is getting a lot better. Only problem is the iPhone is a lousy platform to use as the battery life is less than ideal. And NO, i don't want to buy one of those clunky iCyclingComputer adapater kits for a zillion dollars when I already have a fine HRM/computer. Just no GPS.
Today's training ride http://www.mapmyride.com/workout/50750416/
Getting ready for the annual TdF Challenge.