I would like to recast one of the comments I made earlier, regarding ETech, and turn it into the universal conference law #1:
At all important conferences women make up at least 1/3 of the attendees.
The Wild Boys at a conference like ETech need a lot of socialization, a lot more Wendys, to cut the testosterone.
[Update: Just found The Social Customer Manifesto: On The Conference Thing: Etech, SXSW, Unconferences and Monoculturesa great post, On The Conference Thing: Etech, SXSW, Unconferences and Monocultures, by Chris Carfi on this issue, digging into the nature of monocultural conferences in general and ETech in particular. The ratio at SXSW looks better. Oops.