I'm Percy Liang, one of the coaches. This will be my fifth time at USACO camp (I was a contestant in 1998-2000 and was a coach last year). I went to IOI in 1999, 2000, and 2003.
Like Russ and Brian, I am a graduate student at MIT, but unlike them, I have not gotten my bachelors degree yet as of this writing, but hopefully that will be fixed before the training camp. As an undergraduate, I did some research in algorithms for hypertrees, but then I got lured into machine learning and natural language processing for my masters thesis. Next year, I'm hoping to go to graduate school somewhere else just for a change (though there's nothing wrong with MIT for those of you who are thinking about colleges).
I was born in China, and have lived in Oregon, Washington, and Arizona, before coming to MIT.
The main thing besides computer science that I'm serious about is piano. I've played and took lessons since I was 8. At MIT, I give piano recitals and play in chamber music groups. I also enjoy jogging, basketball, foosball, and using vim.