Critical to blogging has to be updated with new posts. Nothing more boring than looking at stale (though sometimes still useful!) material.
Video links are easily added!

High school chemistry Experiments
video of experiments done by Real Learning Center, a company that sells online education via rich media

Photosynthesis experiment
video of a simple way to show big concepts, done by a group of volunteers who started a neighborhood science club in a village in Pakistan. This kind of material also brings in a global touch to teaching, allowing for discussion around diversity.