I have set up 3 in the last month on the blackberry curve for customers. I haven't had any complaints. It won't be as good as a tom tom or garmin but is nice to have it all in one package.

I have used it, its a pain in the you know where.

I like AT&T a lot better than Verizon, especially with Signal in my area and phone choice, but the one thing they have going for them is VZ Nav.

ATT needs to come out with phones with built in GPS, it shouldn't be that difficult, but you never know.

but I would not waste my money on it, its not worth it.

If you have a PDA that you can download Windows live to, then i would use that with a BT receiver, or just wait until ATT get their act together and have a new windows based phone with built in GPS.

I have sold a few to customers who have had no complaints. I have also personally demoed the service. Works pretty good.

I use it every day on the Blackberry 8800 with built in GPS. It works great!!! Don't know how I got along without it. The live traffic updates and business finder are exceptional.
3D maps and turn by turn are also flawless.

I have downloaded Google Maps and use the GPS with that as well. I find TeleNav a much better application for directions. Although, Google is free.

Hope that helps.