The 8320 doesn't have GPS, but you can use an external GPS puck or other external GPS device, along with BB Maps or Google Maps for GPS location services. Telenav ($9.99/month) is excellent, but requires a GPS source.
The 8310 has GPS (but no WiFi). The 8820 has both WiFi and GPS.
If you download the latest vesion of google maps you can get directions to wherever you're going. It even finds where you are at using cell towers (similar to GPS, but not as accurate). You can also set favorite locations and get directions that way. It is a very useful application.
Once I was coming home from the bar (I wasn't driving ) and got on google maps and searched for pizza in the area and hit the send button on the phone. The pizza was there 5 minutes after we got home.
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