Have you seen TED Ed's new site on You Tube?
This is my favorite in the videos that they have out right now, but I'm entranced of the neat mix of animation and interrelated content. They are also looking for lesson ideas. If you have something fascinating to share, you can go here to make a submission. I'm not sure my content knowledge is deep enough in anything to contribute, but maybe yours is.
Here's another one on space. I've long been interested in space, but I just can't seem to wrap my brain around the size. I get the math, but my brain just can't hold a visual representation of 10^500, as they reference. This TED gives some great visuals and will help you entertain the possibility of size.
This TED talk was given to a bunch of high school students by a neuroscientist. It shows how electrical pulses in the body can be shown and heard, through the use of a cockroach's leg. It is so creative and interesting, that it would inspire me to want to study the brain!