BT-Q890: Qstarz BT-Q890 Nano Keychain Bluetooth GPS Receiver (66 ch MTK, 1-5Hz User Configurable, Auto On/Off)
I bought this to work with my Motorola Droid and an app called Dynomaster.  The BT-Q890 was recommended by the author of the app as a way to get the GPS to update at 5Hz instead of the phone's 1Hz.  This worked great for my recent Autocross event where I was able to track all 20 of my runs and download them to Google Earth and Excel.  The updates every 0.2 seconds made the tracks much more useful and informative.      The BT-Q890 easily synced with my Droid and ran the whole day (at least 6 hours)without re