This article from IBM developerWorks, describes how to "Meld buildings' directories and maps of their interiors to create ad-hoc maps of people, meeting spaces, and other assets", using Perl, ImageMagick and The Gimp. As usual there is a "Rate this page" form at the end of the article.
Martin
Comment on Map places, people, and relationships inside a building with open source software
This is the kind of stuff you could make money with as a freelancer......
I immediately thought about a real-time system using Tk, where everyone's position is shown in realtime (maybe by RFID units on their id-badges.) Just like "24". :-)