Digital Learning Environments is a site sponsored by HP and Intel that offers resources and ideas for teachers on how to use technology in education. There are some great ideas and lesson resources for all teachers on the site.
This page of the site has a listing of Web 2.0 resources to use in Science Classes. Resources listed include a varitey of sites listed by subject. There is a brief description about the site and how it can be used in the classroom.
I recommend this page for all science teachers and Digital Learning Environments in general to all educators as a must have resource.