Holux GPSlim240 - GPS receiver module
Since there is no physical interface other than the On/Off Switch and the charging port theres not much to complain about.  The unit is really small, shorter than a stick of gum. I paired it with my Nokia phone (6120 Classic, S60 OS), went outside, waited for a few minutes for the flashing light and ran google maps with the myLocation feature set to GPS.  -Bingo-.  Now you need to understand that this unit is only a GPS sensor.  You turn it on and it starts sending serial data over the blueTooth port.  You 