Let the hive mind of Engadget get that for you.
"As someone who doesn't reside in the USA, I was wondering what would be the best way to get internet for my computer in the US for a couple of weeks? If it were Europe I know I'd look for some prepaid data. Is there anything similar offered by American carriers? A MiFi or a data SIM that I can tether from would work, but I'm trying to maintain a tight budget. Help!"
I had a Navigon 700 for nine months. It was glitzy but FAILED at core functions. Routing was terrible. I don;t mean it had some occasionally strange routes, I mean it always routed badly. If you read various forums like gpspassion you see that the idiotic routing is objectively compared to Garmin, TomTom and Google Maps.
Want to see how serious Navigon is about its US operation? It has been here a year and you cannot buy a spare proprietary mount if it breaks (and they do) or its proprietary usb head chargers. My mount broke after 2 months (Nov 2007). They told me each and every month they would be selling accessories the next month. They put up a laughable bunch of accessories like screen protectors and pouches. They finally told me that I could buy the mount through Navigon Germany. $160 to shipped. thanks.
They finally updated the software after about six months. It broke the ability to even save favorites (you already cannot add POIs). saved favorites come up as invalid now all th time. I got rid of mine but from forums you can see this is still not fixed.