I have a program called "Eat, Sleep, Ride" on my Iphone.
It does display an active map while you are riding - but no speed. When the ride is over it will show you a lot of data about the ride including time, total length, maximum lean angle, maximum speed, and you can display and review the map of where you traveled. You can share these rides on the Eat,Sleep, Ride forum......most folks don't bother.
The app. is free - however if you subscribe to the "CRASH" feature, it can identify the physics of a crash, and if you don't respond to the request the phone makes.....it will call for help and identify your location.
For my Iphone 4 - it is necessary to have the phone connected to a charger when on the bike, as any navigation program really uses the battery quickly.
http://app.eatsleepride.com/