I went to siggraph for three days this year, rather than the full week. I tend to get exhausted at siggraph--it's non-stop learning, catching up with people, socializing, seeing incredible ideas, and sneaking in a few hours of sleep a night. I took a 6am flight down to see most of the morning sessions and decided that shuttles are still too much of a waste of time (it took well longer to get from the airport to the hotel than the duration of the flight).
There were two big topics at the conference I was interested in. The first is controllers for character animation, mostly in terms of walking. The big trend this year was the use of simplified physical models, especially inverted pendulum models, to plan and control the motion of more complex articulated characters. Having seen some of this work grow to maturity behind the scenes before it was published, it's nice to see a large portion of the field thinking the same way about a problem. In coming years, if the presentations become more concise and the ideas are generalized to more types of motion, this could start to have a big impact in the game world.
Fluid simulation is the other area that work that really caught my interest. Surface tracking is a big thing, using geometric processing steps interleaved with simulation steps. The detail looks great, although some approaches are somewhat conservative in terms of trying to keep things from breaking apart. There's also interesting work on adapting grid resolution and non-grid domains for specific simulation steps to increase detail.
The electronic theatre was great this year. Some years it feels gimmicky, but many more pieces were quite original this time. Some favorites are The Light of Life, Loom, The Lost Thing, Poppy, and Upgrades.
Emerging Technologies can be hit or miss, but there's usually one or two things that are really really cool. I only saw about a third of it, but a friend pointed me to a voice-responsive zoetrope from Disney, which was made using hand drawn expressions on ping pong balls. It has the right mix of hand-made originality, technical wizardry, and charm, which probably makes it the most fun thing I saw all week.
Of course, siggraph has parties. Since we started our own a couple years ago, I've become less interested in finding them as opposed to helping put one together. We handed this year's organizing off to UBC, who did a great job. The number of people doubled again, which is good, and quite amazing considering the small group on a patio that it grew out of a couple years back.
One final thought: The food choices near the conference center have significantly improved since two years ago, although I did end up on one walk with someone who stubbornly believed there had to be something good a little further away too. He was proven wrong, of course, but most people have to see downtown LA culture to believe it.