Here is a picture of the whole setup, up and running....
I have successfully created a bluetooth link from my X3 without using my SD slot. It's not a totally wireless solution, but it lets me place my GPS whereever I want.
The serial cable also charges the pda at the same time, so you do not have to worry about using your battery.
What I am using is a NAVMAN 4400 GPS that has bluetooth.
I have created a rs232 serial port that connects to the bluetooth navman with the socket cordless serial adapter, I could get away with this because both the serial adapter and gps use SPP (serial port profile).
Here's the picture of my setup.