A few months back I made three short high-definition astronomy videos with my partner Tom Lucas, and we put them up on Hulu and Vuze. We know that makes things difficult for non-US viewers [edited to add: I have been told Vuze is viewable worldwide. Sorry for any confusion there.], so we've finally got the videos up on YouTube! Mind you, the resolution isn't as good (though YouTube does have higher-res versions now), but hopefully you won't mind.
Here's Black Hole Death Rays:
We also have one called The Changing Face of Mars:
And the third is Cookbook of Galactic Cannibalism:
We're in the process of making more of these right now, and of course I'll post 'em when they're ready!