Woo science! Glad to see it have its own thread. I can't think of anything to add at this point to it (besides how awesome the potentials of nanotechnology are) but I will second that David Attenborough is a pimp.
EDIT: I forgot about Carl Sagan's Pale Blue Dot. Definitely a cool video.
A Pretty cool and simple video on the subject of wave/particle duality and the double slit experiment (I'm biased as a chemistry major).
The ending should be taken with a grain of salt though, as for what I know, the electrons "being watched" isn't what makes the electron behave as a particle, instead I'm pretty sure it deals with some sort of interference brought on by the thing observing the particles.