Just got back from 10 days in Cali (5 in SF 5 in Mendocino) and got a chance to view the first day of racing on the bay.
I'm not too excited about a bunch of ga-zillion-aires flaunting their respective disposable cash caches but the technology behind these boats is incredible.
I first read about Oracle's Ellison teams coming up with these water rocketship/airplanes in WIRED awhile back but actually watching the American and New Zealand entries was amazing.
http://www.wired.com/magazine/2011/08/ff_americascup/Fun stuff on a rarer warm and sunny day in The City.