Turn by Turn Nav on custom maps?

[BumbleBeez]

Is there a Nav app for the iphone that will allow me to have turn by turn spoken directions on maps I can make and import, or even just build custom ones in the app itself?

Basically, I want to be able to go on a group ride (motorcycle) and record the route (I have software that will do this part) ... then be able to someohow load, or plot, that route in some Nav software, and have it give me turn by turn directions so I can repeat the trip myself.

Is there anything out there that will do this? I can't be the only one wishing for this type of functionality!!!

[blkcadi]

If I am not mistaken, Google earth will do geo-tagging. May not be what your looking for. Search the App Store and you may find something that has voice also. Sorry I couldn't be of much help.