This UC Berkeley page has a long string of text with a lot of summer 2010 research opportunities... go to http://research.berkeley.edu/otheropps/summer3.html and use the "find" option in your browser to search for keywords of interest.
It's a grab-bag, includes some non-science internships too!
And then, this page http://research.berkeley.edu/opportunities.php?option=bawayb has a few listings of summer interenships that Berkeley has flagged as off-campus opportunities.
