The Pocket GPS Portable Navigator combines the portability of a CompactFlash GPS receiver with Ostia, Pharos' award-winning street routing and navigation software. With the navigation software installed on your Pocket PC, you can drive or walk through any city in the US, and locate your current position or quickly find a destination or point of interest. The automated voice prompts will instruct you when and where to turn. If by chance you go "off-route," the automated voice will give an off-route warning and the system will automatically reroute you to your destination from your current position.