Open Hardware Summit
The Open Source Hardware Summit was amazing - Dave & I attended for the first time, and got to rub elbows (no choice, it was standing room only!) with the Open Hardware elite.
The content was very diverse, and the speakers were quite good overall. I've been to a TON of conferences, and this was one of the best I've attended.
I particularly enjoyed the Arduino team's slides, the Instructables slides (community K'nex gun development - wow), and Bre's slides with his challenge to us "Publish that Crap!"...
Slides are being posted on the Summit Website - http://www.openhardwaresummit.org/documentation-2011/
Note that a member of the Protei Open Sailing team is speaking at TEDx Orlando in November (Shameless plug -> Have your ticket yet?!) http://tedxorlando.com/