The site Physics.org is holding a 2010 award contest for science/physics websites! I wrote about this before; since then they've closed nominations and have short-listed five sites for each of the categories, including best blog, best online magazine, and so on.
They asked me to judge the "Best ask the expert / Q&A site" and I can see my work's cut out for me.
But you can join in: beside those of the judges, they also want the public's opinion: there's a Peoples Choice award in each category as well. All you have to do is register with the Physics.org website, and then submit your vote. The polls close on Sunday, November 7.
There are lots of good entries, and at the very least you can take a look to see what sciencey sites are out there you may not know about.