I just wanted to post an update on something new I'm working on called BlueBlabber. I tweeted about it earlier today. It's a bluetooth proximity app like BlueTracker and BlueTrackerScript. BlueBlabber mixes BlueTracker and Blabber together, removing the xPL component, and communicating via IM.
I built this to use at work. At my previous job, I used BlueTrackerScript and scripted up HTTP GETs to my webserver - one URL for when it detects my phone and another for when my phone disappears. I figured I'd try out this method since I've been IMing status between homes. I've been tweaking it the last couple days and I should be releasing it shortly.