This website is still coming online, but there are some videos up currently. NASA is creating this database of videos geared towards different age groups to help them learn about science and engineering. I know there are plenty of parents or otherwise interested adults around here, so feel free to take a look.
I have the NASA TV gadget on my Vista sidebar. You get heaps of Documentaries and feeds from the ISS etc. Sometimes you get some great stuff, like lectures and presentations. I suggest if any one has Vista to download it.