Wesabot is a Campfire bot framework we've been using and developing at Wesabe since not long after our inception. It started as a way to avoid parking tickets near our office ("Wes, remind me in 2 hours to move my car"), and has evolved into an essential work aid. When you enter the room, Wes greets you with a link to the point in the transcript where you last left. You can also ask him to bookmark points in the transcript, send an sms message (well, an email) to someone, or even post a tweet, among other things. His functionality is easily extendable via plugins.