I think the integration of phone systems and business managment software is still WAY too seperated. In the quick video below cingusoft show an interesting possibilty using a $80 RFID reader, an XML enabled SIP phone and a Windows PC. (ignore the corny introduction)
Let this example get your creative side pondering.
I know a while back I talked to a 3CX VAR who was working on a hospital phone system that would locate personnel via RFID and ring the nearest extension to them! Interesting possibilities with these kind of mashups.
Where to get RFID stuff: