so I just got my Jabra BT250 (Bluetooth headset). I must say this is a great device and works really nice with Linux (BlueZ). First thing after playing some stupid wav files on it was to point XMMS to it ... works like a charm ;-) Also the range at which this device can receive seems pretty huge.
And yes it also works nicely with my iPAQ h6315.
Last test to still to be done is to get one of the many VoIP applications to run with this (e.g. Skype).
One last thing ... turn your PC into a Bluetooth bullhorn using:
arecord -B 1000000 -D plughw:Headset - | aplay