Nokia 770 + a random Bluetooth GPS + Maemo Mapper + Google Maps = fun.
Nokia 770 and NaviLock BT-308 GPS
The fun part consisted of
- Patching Maemo Mapper so that it can use Google satellite map pictures.
 - Banging my head against the wall trying to understand why Maemo Mapper won't talk to the GPS today, when it worked perfectly yesterday.
 - Googling for BT-308 protocol descriptions.
 - Discovering that BT-308 speaks two protocols: NMEA-0138 text protocol and SiRF binary protocol.
 - Discovering that Maemo Mapper only speaks (well, listens to) NMEA-0138.
 - Discovering that gpsdrive/gpsd that I tried yesterday evening (without much success) tell the GPS device to switch to the binary protocol (which is apparently the same that Garmin devices use).
 - Discovering that turning the GPS off and back on does not switch the protocol back to NMEA.
 - Reading the SiRF binary protocol refeference manual and writing a short Python script to connect to the GPS via Bluetooth and tell it to use NMEA.
 
Maemo Mapper