On the weekend I bought a Bluetooth Mouse to use with my notebook that has an internal Bluetooth adaptor. It was great to see it working under Linux in no time at all after taking a look at the following page.
Bluetooth looks like a really great technology for peripheral devices, etc. There's also two implementations available for Linux, BlueZ and Affix which both seem to be quite advanced.
Next I'm going to have to get a Linux compatible 802.11b/g Mini-PCI card with a base station too! Then I'll be completely wireless :)