Ah-ha you bought one as well in the PC World sale huh? Me too! I've not tried linking via Bluetooth, as I've got the Wi-Fi print sharing going on - but I would imagine that it would cause you problems as the Photosmart printers rely heavily on the software installed and the communication via the USB port.
I have seen a few USB devices, but the only ones I have seen that work with HP products have been parallel ones (not saying that USB ones that are compatible don't exist).
To be sure, you have installed the software package that comes with the printer on the computer you're using the bluetooth on haven't you?
I had a quick look on the support pages for the printer, and there's no mention of Bluetooth. I suggest you drop them a mail through the website to find out for sure - I've been very impressed with the speed they come back to you via email - usually within an hour or so.
The page to do this is here:
http://h20180.www2.hp.com/apps/Conta...photosma305379
One thing I've noticed is the severe lack of general info about this printer on the web. I think this has a lot to do with the fact that it was sold (in the UK at least) only via Dixons Group stores (PC World, Currys, Dixons). If you find this too, then it's worth doing a wider seach on the Photosmart 7760 or rest of the 7700 series printers.
HTH
BTW...there's a new driver package available on the HP website...it's about 40meg though, and doesn't mention Bluetooth anywhere!