When I first started a class wiki, I relied upon Teacher Tube a lot. My tech coach recommended it (thanks Amy!) and I used it to post student-made videos in a way that allowed only private access. I didn't want complete strangers looking at the children's work. As time went by, other sites, like School Tube, offered faster and more efficient processing.
When I am searching for videos for lessons, I usually look at Discovery Education and You Tube. I was surprised that You Tube had so many quality videos. There are a lot of phenomenal teachers out there, and they are posting videos of their lessons. Some of them helped me teach 4th grade math and science this year. I've also used You Tube videos of news events from ABC, CBS, and NBC for learning center activities (with iPod Touches).
Here's a video of a professor using a cookie to explain how tides work. It certainly helped ME understand them better!
Here's a fun teaser I used when I was starting a unit on states of matter. What do you think? Should we call Myth Busters?
I'm still not crystal clear on what the copyright laws are. They don't seem too well-defined -- a lot of gray areas! I encourage students to cite photo sources whenever possible. If there is a copyright symbol on pictures, or a watermark, we don't use them. I encourage students to use license-free music.
I like the Photopin website. Hadn't ever tried it before! I also like the sites that allow you to strip all references to You Tube. Both were new to me and will come in handy. I don't like the idea of 2nd graders hitting links within You Tube and going on age-inappropriate adventures!
I've used Dropbox a lot. It is a fast way to share files from my home computer to my school computer without using Google Docs or email. It was also great for making videos accessible to students on iPod Touches. Instead of having to sync all of the iTouches, I can have the kids upload them by clicking on the Dropbox icon.