If you have been keeping up with the GPS market for the iPhone, you know that there are two or three main contenders. Gizmodo has a good wrapup of TeleNav vs. Navigon vs. TomTom to figure out "the best" (or at least, the best for right now.

No matter which app you're using, the GPS runs constantly and the screen generally stays on, which means utter battery drainage: You will need to keep your iPhone plugged into the car's lighter jack. You will also need a dashboard mount, which range from $10 to $30.