I was just sitting here working and noticed on my AIM buddy list that someone had gone red. That is, they marked themselves as "being away" even though they're still logged in. This of course is perfect. One of the things i like most about IM is presence; that is, knowing when someone is around in my virtual world. The problem is that people don't usually do this. They let the machine mark them as idle (not bad) or log out (which means they could be there and just not logged in). What I want is for my computer to know when I'm there and when I've stepped away...even if I'm not using it. The great part is that I have all the pieces that would form a solution right now.
I use bluetooth on my powerbook and have a Sony T68i bluetooth equipped phone. I want iChat to mark me available (unless I override) whenever my powerbook can see my phone and mark me away when it can't. My phone becomes my "presence" token. I don't know if iChat has the right hooks to be able to script something like this or not, but it would be a neat feature.