These are a few of my favourite's so far:
Jill Bolte Taylor: My stroke of insight
Barry Schwartz: The paradox of choice
Sir Ken Robinson: Do schools kill creativity?
Al Gore: New thinking on the climate
And a couple more thanks to Kelvin:

Something that's been lingering in my mind for a while now is the idea of shooting the viewer... reversing the roles. I shot this maybe a week ago in the very early hours of the morning and had given up on trying to sleep and decided to watch One Flew Over the Cuckoo's Nest. It didn't really help in making me feel any saner. But I like the image. I think it was about a 10 second exposure and I haven't really edited it in post yet but its just a sample. I like the composition of the shit all over the room (for the image, not reality). I was expecting the light to be bluer. I tried a similar approach another time, I had two subjects on the couch and looking into the camera. I shone an ancient slide projector onto them and the background, as if the images from the TV were absorbing them, but the effect didn't work out as I'd hoped. I then just threw a primarily blue image into the projector and moved it back so it was less intense, and tried again. I need a better lighting arrangement for it to be effective. I really wanted a full-frontal approach, as if I was taking the photograph from inside the television and they were looking at me... but the image above has questioned my desire for that. I'll do some more experimenting and see what works. I like the idea of seeing a bit more of the surrounding environment. I just realised this is a bit similar to what Joanne's doing. She said she's doing portraits of her family, firstly her dad, surrounded in his escape; books. I guess it depends what theme I go with.