Try these:
http://csmp.ucop.edu/cmp/comet
Pacbell for indexing mathweb sites
We offer collections of links to math sites in three sizes!
Small
for those teachers who want to look at just one site. (picked by one of the RAMP staffers every month)
Medium
for those teachers who have a bit more time to explore
And Large
for those teachers who are not intimidated by over a thousand math sites.