You definitely wouldn't want to customize the Jabber client; that would defeat the purpose of having multiple conduits to different devices.
What you *could* do, however, is use Jabber as a very simple (English-like) command line interface for different components. Imagine, for example, having a connection open in Jabber to your ticket-tracker instance. You could ask it to "List commands," and it would give you a list of the various things you can tell it to do via IM. One of those things might be "List my tickets." Once you get a list of your tickets, you might tell it to "Start timing foo." Later, you could tell it to "Pause timing foo" or "Resume timing foo."
Obviously, you wouldn't want to get too carried away with this, but you could develop a very simple interface to do crucial tasks you want to accomplish when you either don't have access to a full browser or you want to time-stamp something over an unreliable connection. You could do all kinds of things with this. For example, you could restart a hung server using your two-way pager.
An added benefit to this is that, by having IM connections open to a bunch of packages at once, you'd have quick and easy access to issue commands to any or all of them. It wouldn't replace the web interface, but I could imagine situations in which this sort of interface would be handy and convenient.
