I also use ridewithGPS and send it o my Garmin.
Powertip - go through the "turns" and delete the stupid ones (a lot of "Stay straight" or other turns that are too obvious to bother printing, along with the turns to get out of your neighborhood) and then copy the cue sheet to some other program and print it out. I typically tape them to my top tube (although I rarely use them)
How does that google maps thing work? I use it in my car fairly often. I get that it says it will do turn by turn but can you pre-program your route? I don't necessarily like going the most direct route. It would be a great safety net if you get lost though.