Ryan Disney , Feb 12, 2006; 07:51 p.m.
I might be perpetuating a rumor, but I've heard that if you leave the lens in the direct sun for a while it will dry out and kill the fungus. Being a biologist, it seems plausible. It should keep it from getting worse, and will probably make it a bit clearer.
I could be completely wrong, as I've never had to try it.