How did you use your projector today?

Hi All!
I want to create a little space on the Internet just for us. Now that projectors are on their way to getting hooked into the ceilings permanently, I was thinking that we should really get started sharing the ways to successfully use them to teach.

So - How did you use your projector today? Let's start a list. Maybe we can create a "Top Ten Ways to use a Projector to Teach" list?? (I know that some projectors are in the computer lab closet and unavailable to you - please use this time to read about fellow teacher successes and plan for the future :-)