Minutephysics is a youtube channel that produces weekly, minute long videos about... physics (and maths sometimes too, but from a physicist's perspective).
I think the videos are great. I think the guy behind it is very talented. One small caveat should be given before I link you to some of my favourite videos he has made. He limits himself to explaining, in just one minute, some topics that are quite intricate. As a result he sometimes has to be a little liberal with the truth. I wouldn't say that anything he says is wrong, but I would say that it is often a highly simplified version of the truth, sometimes missing some very important pieces.
But if I put that caveat aside, I think minutephysics is an excellent and well executed idea. The video I've embedded above explains Dark Energy. It isn't actually the minutephysics guy talking but is a guest voice-over from physicist and prominent blogger Sean Carroll. So, if you're wondering what those guys won that Nobel Prize for a few weeks ago, have a watch and see (but do keep the truth-ness caveat in mind).
Really all of the minutephysics videos are worth a watch, but two of my favourites are:
You should definitely watch both of them.
The feat of mathematical craziness worked through in the first one should blow your mind a little. You probably won't believe the claim made in the video, so check out this link to understand it a but further. If that isn't enough crazy for you, check this link out. This sort of crazy mathematics has some application in physics, but I don't feel confident enough right now to try to walk that minefield of balancing understandable explanation, without falling into over-simplification.
I really like the second video. I will explain why sometime later in the week in the comments. Anyway, it is also a (loosely) relevant video given the recent conversation about light that developed in the comments here.