Well, I really don't like having a cell at all, but my contract w/ Verizon ended and my wife, bless her little heart, got me an iPhone 3GS to replace it.

This thing is cool.

Besides getting "apps" (short for "applications"), for sports and stuff, I had to find one to replace my older Magellan GPS unit as I "loaned" it to my brother. It is somewhere around Tuscon. Or Lake Geneva.

Lots of free "apps". And $.99 ones. Cool ones. As I was driving back home through the wilds of West Alabama Saturday night/Sunday morning, I was using the GPS map: App Store - MotionX GPS Drive

And was wondering why my UltraGauge was reading 77 MPH when my hated 2000 Accord speedo said 83 MPH. (Large amounts of food travelling cross-state to my 320 lb son precluded driving the buggy). The MotionX doesn't have speed display (for $1, what can I expect?) So I started looking for a GPS speedometer. Found many. All work, and agree with my UltraGauge. The Accords' speedo is off.

Many $1 and free HUD speedometers. some with other info, some barebones.

aSmart HUD for iPhone 3G, iPhone 3GS, iPhone 4, iPad Wi-Fi + 3G, and iPad 2 Wi-Fi + 3G on the iTunes App Store
App Store - speed HUD
App Store - Car Dashboard

And my favorite:
App Store - Awesome HUD

Anyone else do this? A dot of Velcro or a low-profile mount to keep it in place on the dash about 6" from the defroster vents. And low. Don't want to block my vision.

It needs to be charging while on GPS or it will only last ~ 2 hours.