DS Screenshots (how-to??)

Hi, I'm thinking about starting a Nintendo DS website, but I don't now the possibilities of taking ds screenshots and/or videos without taking a picture of the whole ds, but just getting a screen capture. I know its possible, seeing the IGN and GameSpot do it, and I know that there is something you have to buy to do this. What I want to know is what is this device called that allows this, what you need in order to have it work, its price, and where to obtain it.

emulators?

I would suggest that places like IGN and GameSpot are supplied the screenshots, they do not create them themselves. more likely to be from nintendo press release or press pack.

Well this has been bumped quite a ways....But I think that they use the Nitro thing....can't remember its full name, I think it's part of a development kit