So far I haven't had any trouble connecting my Motorola Bluetooth headset to my Sony Ericsson phone or PC, but have had trouble connecting the phone to my PC. I think this has more to do with poor and sometimes confusing software than the Bluetooth standard itself. My headset works ok in MSN Messenger, although it seems to have trouble with echoing what the other user says back to them. This may be due to the drivers that my Logitech Bluetooth hub uses, which apparently inlcudes more of the Bluetooth abilities than many other adapters.
Bluetooth does make it easier to sync my contacts etc. with my PC now that it is working though. My PC also picks the phone up as a modem too, although I disabled that connection as the computer kept asking what internet connection to use.
goates