I just wanted to post my first impressions on TeleNav for the BB. You can only use it with the BB 7520 through Nextel as it uses the GPS capabilities.
Installation was easy, you add the program through the Application Loader just like any other program (there is no way for OTA that I could see but that may change). Setup was also easy, you give them your credit card number and they start billing you after 30 days. You do get the first 30 days free.
I must say this is the best program I have ever used for the BB!!! There are many different ways of entering your destination in and they all worked extremely well, even the automated operator to call in your destination.
What really impressed me was how Telenav responded when you took a wrong turn. It recalculates a route and gets you back on schedule quite quickly.
Anyway, all you 7520 owners, check it out! Its well worth it.
BTW. I have no affiliation with TeleNAV whatsoever, I just really am an impressed customer