One thing I forgot to mention about it...

It does that nifty trick of showing you your speed and direction based on your historical position data. For example, your position indicator on the map is an arrow showing which way you're driving, and there is a MPH indicator indicating your speed.

What I find most interesting is that the GPS software consitently reads 4mph slower than my speedometer does. Does that mean that my car's speedo is actually calibrated a little off so that I drive slower? Or does it mean that there's a bug in the GPS software?