I did a gnomon masterclass last year, its a brilliant course and taught me allot about lighting, rendering and sculpting. I wouldnt be half the artist I am without it, it might not be blender orientated, but this is done by the people who worked on Avater, and District 9 and so on
you’ve even got a chance to win free entry if you go into the forum:
http://www.gnomonschool.com/master/2011/
Trust me when I say that if you miss it, you’ll regret it.