adNav Boomerage - Ad-Supported GPS

The idea is to more or less "rent" an adNav Boomerang for little to nothing from car rental agencies, hotels, etc. The catch is the advertising that comes bundled into the software.
via: adNav Boomerage is an almost-free GPS unit, with a catch | SCI FI Tech for Wednesday, October 24, 2007 | SCIFI.COM
related: adNav Boomerang, the ad-based GPS "conceirge" - Engadget
Free, Ad-Supported GPS Gizmos Coming on Gadget Lab