extended jabber presence - including detection

This is another idea seeking for some implementation - Having the idea of the desktop daemon in mind… why not enable the clients to update the presence information of a jabber user by themselve? I will work like this:

• there is some kind of presence/location sensing network, this will determin where in my home/office/campus/… I am
• my presence/location information is published at some local pubsub service
• my client (gabber, Adium, gossip, …) has a plugin which is subscribed to that node, heance receiving my presence/location update
• the client’s plugin determines rule-based if it should set my JID’s presence according to the update it just received

The “location sensing network” could be a Sensor Network like bluetooth enabled campuswide kind of thing or some cameras and a good piece of software doing image recognition, or some other thing which automagically detects where I am.