I've paired my iMac and the 770 up, but can't seem to be able to BT file exchange with it, the same way I do it with my Treo 650. I just got my 770, so I am very new to this. Thanks in advance. I still can't pair my Treo 650 and 770 to connect to the internet, it times out.

Out of the box, the 770 doesn't run an OBEX server. Other devices can't browse its files over Bluetooth unless you're running one. You can download a third party one at http://maemo.org/maemowiki/ApplicationCatalog