Bluetooth is the wireless local connectivity standard supported by current Openmoko and Neo1973.
There is a non-functioning panel applet Bluetooth Connection Status.
For now, see Manually using Bluetooth, which also explains pand networking for setting up a tcp/ip over bluetooth.
Safe Bluetooth connection through shaking of two devices
The accerelators of the Neo should make it possible to realize the following idea:
Take two Neos and shake them together => the synchronized shake establishes a safe Bluetooth connection between the two devices.
A demo video: http://www.youtube.com/watch?v=ktJC0S4_X58