Do a search to find more on this. But the US Cellular 8130 GPS is not terribly good. It requires line of sight with satellites, and can take several minutes to lock. Sometimes you have to reset the BB (battery pull) and clear the cache to get it to lock. Essentially, it is a gimmick that has some use but rather limited. I love my Pearl, US Cellular has good service in my area, but the GPS should never have been released as it is.