I found this in one of my email groups. My boys love this kind of cartoons that explains interesting and complicated matters. If you go to Youtube, you will find more episodes.
That reminds me of these series from the 80's. Some of you might remember them. We've bought the 'Er was eens....de mens'/'Once upon a time...man' series, (starting point is evolution, noticable in the intro and the first part). We've also bought an other serie 'Er was eens...het leven'/Once upon a time...life', but that got stuck somewhere in Holland. Looking forward to watching that one on dvd too!
I couldn't find reasonably priced dvd's on Amazon.co.uk, but the Dutch are more lucky this time, because you can buy them at Bol
And last but not least, I got this one from Josh...
And this one, about quantum mechanics (unfortunately only in Dutch (Flemish)) from Jan Paul Schuttens' blog
(sorry about the title, that's misleading!)