[Heinous]

I tried turning off the display with psShutXP. Sprint Nav continues to navigate and give directions, but it lags and updates so slowly anyway that it's unusable. TomTom won't continue with the display off, but it will while the phone is locked. However, when the phone is locked the display eventually turns off and TomTom will stop...

I haven't tried Garmin or iGo8 yet.