The first talk (by Dana Moore and Bill Wright) presented Jabber as a way to control distributed software agents. The user fires up a Jabber client and his "buddy list" consists of all the different agents that are floating around the system. He can send chat messages to interact with each one, getting info such as "help", "status", or directives such as "kill cpu" (their project involved agents that attack a distributed system to see how it holds up).
I really like the idea of using Jabber to communicate with "headless" software in general. The usual solution these days seems to involve embedding a web server into the program, or maybe telnet--and that's if the software has a user interface at all. More commonly, input is restricted to config files, environment variables, and command line switches, and the only output you get is a logfile.
Embedding a Jabber client in your program is much lighter weight than embedding a web server: all you need is a client library (the Smack library for Java, for example, weighs in at 124KB, while Jabber4r for Ruby is less than 75KB) and maybe a thread to poll for messages (I assume--I'm not too familiar with the protocol yet). And sending warning or error messages to an administrator through Jabber is much more likely to get attention than if the messages are simply written to a logfile.
I'll refrain from going into any more detail until I've tried this with one of my own projects. If and when I resume development on my IMAP server, I'd like to use Jabber as the interface to add/remove users, reset passwords, and other administrative tasks.