Some people have issues with GPS accuracy, such as showing your location 1000 feet or further away from your actual location, and this can be resolved by following these steps.
1. Download GPS Status from the market (it's free).
2. Make sure your GPS is turned on and open GPS Status.
3. Go to a location where you don't have magnetic devices around you (like electronics of any sort), such as outside (ideal) or room with minimal electronics nearby.
4. Hold your phone in your hand flat. Spin it around 3 times. After that, hold your phone on it's side, spin it around 3 times again. Finally, put your phone right side up (end on end) and spin it 3 more times. You can also do figure 8's, but the spins worked for me.
5. Go to Google Maps and see if your location is closer.