The hallways track is always the most interesting track. The people I normally want to talk too are there. This means that for me I normally weight conferences based on the people I meet, not on the content.
Open Source Bridges is different. This was the second year I attended and I was once again I found myself thrilled to be going to talks :)
I'm not sure why, but OSB seems to have a different audience then other conferences I tend to go to, and each year I am amazed at the talks that I listened in on.
Short list (ie, my favorites):
Hacking Space Exploration -> http://opensourcebridge.org/sessions/383
Practical Facebook stalking with Open Source tools -> http://opensourcebridge.org/sessions/425
The facebook talk was one of the funniest, and informative that I have heard in a while. The space exploration one was neat because I knew so little about the topic and yet I was able to follow and learn quite a bit about the current state of satellite creation/participation in the drive for space exploration.
As far as being a speaker? The audience asked a number of intelligent questions and I think I could have went a bit deeper into the subject, which was Drizzle, then what I normally can. As a speaker it is nice every so often to be able to dive deep into a topic and feel like your audience can follow along.
I wish they would have done an Ignite style talk at night, I would have loved to have seen what talks people might have presented.
Portland is a pretty awesome place to throw a conference. The public transit works, there are affordable places to stay, and there is a built in audience of geeks in the city (probably larger then my hometown Seattle, which for some reason lacks a very active technical geek audience).