A couple months ago, when I was at ZendCon08, I spent a good amount of time chatting with Chris Cornutt (eygma on IRC and Twitter) who is also the founder of PHPDeveloper.org. One of the things he showed me was his pet project: Joind.in
One of the odd things about many of these tech conferences, is how speaker/session evaluations are handled. At many of them, the room manager hands you a printed evaluation form. You write your comments, mark your scores, and turn it in. And finally, month or so later, the conference organizers get back to the speakers with the scores. For a tech conference with a tech audience with tech speakers, this doesn't make a lot of sense.
In comes Joind.in to fill the gap. It's a simple site listing a bunch of recent – and near future – conferences so you can score and provide feedback online… it doesn't matter if it's immediately after the session or after you get home. The point is that speakers – and other attendees – can get faster feedback on the sessions and find out which ones get the most interest. The events listed so far – phpAppalachia, PHP NW, and PHP Works are just a small part of the conference circuit, but they're a great place to start. I think it will get even better as different unconferences and *Camps get onboard.
An area for improvement: The primary issue I see at the moment is that anyone can register and leave feedback on any talk. There's no validation to ensure the person actually attended the session or even the conference. Unfortunately, to do this validation, Chris will have to get buy in from a few conference organizers to share their lists. I think this is a unique opportunity that I hope one of them will take.