Jing
Jing is a very cool application that allows you to quickly capture images, record video of what you are watching or what you are doing, and then share it online by uploading it to email, IM or blogs.
You do have to download software to your PC or Mac to get it to work. It then resides as a half-sun at the top of your monitor, waiting for you to need it. By running your mouse over the sun, you will get some options of what you can do.
It is easy to use, but I warn you that you can get lost in the menu system wondering why you can't click some options. Just make sure you don't have another menu listed under the area you are trying to work in.