Although these aren't the greatest or most entertaining resources, there are different videos that could be useful to a teacher that include training on how to use the technology that is available to them in their school.
This has activities applicable to language arts, social studies, math, and science for grades Pre-K through 12th grade. They were actually pretty interesting. Very diverse.
This website has lesson plans, but especially it has tons of web resources. One of the coolest ones I found was http://web-japan.org/kidsweb/, where there are so many resources to use if you were teaching a unit on Japan. That's just one example. There are tons!
A member of our class shared this on their blog. It's another great site for finding material with flexible copyrights that are easier for us to use and reuse on the Internet or in projects.
This website provides free study guides for many subject areas, including Literature, US History, Poetry, and Civics. I am way excited about it, because teachers need study guides sometimes, too! It would be a great way for students to find a compilation of information to use for projects or to study for tests.