Here are some resources using Web 2.0
Internet4Classrooms
http://www.internet4classrooms.com/index.htm
A portal of high-quality, free Internet resources for classroom instruction, developing project ideas, reinforcing specific subject matter, and tutoring in the class and at home.


Google Lit Trips
http://www.googlelittrips.org/
Take a virtual field trip to the settings in a variety of classic literature.


Virtual Manipulatives
http://nlvm.usu.edu/en/nav/vlibrary.html
A digital library containing activities for K-12 mathematics.


Gizmos!
http://www.explorelearning.com/
Interactive online simulations in math and science for grades 3-12. Fee for service but free 30-day trial is available

Web 2.0 to Go
http://www.go2web20.net/

A selection of online tools and applications on one page.