KDE Bluetooth is pretty slick; if you have a phone with bluetooth, that is ;)

It's able to send/receive files from OBEX compatible devices through Konqueror, and it has a nice program to do call-management (answer, hangup, deny, place calls; show caller id). It also does device detection, and can execute arbitrary commands when devices come into or leave range. Things that would be cool are placing your IM program into 'away' mode, or turning your screensaver on (and locked!). It has lots of potential. Of course, there's an RPM of it ;)