I think so, and I think it's called the Meat Stylus:

http://www.weirdasianews.com/2010/04/04/south-koreans-revolu...

http://kottke.org/10/02/meat-stylus-for-the-iphone

I ended up buying a blank felt tip marker and filling it with water. It works pretty well for me, it also has the added benefit of washing off my fingerprints from the screen. (not terribly sure why this is getting down voted; this really is what I'm using for a stylus)

Pretty slick Make video.

For a little bit of cash you can snag a nice ipad (or iphone) friendly stylus here: http://www.overstock.com/Electronics/Stylus-Pen-for-all-Appl...

There's quite a few available on Froogle:

http://www.google.com/products?hl=en&q=capacitive+stylus

They would probably also work with other touch devices: droid, nexus one, laptop trackpads, etc.

I own the Pogo Sketch. Although I can write with it, I almost have to do it 90 degrees or else the iPad doesn't sense anything :/

I'd pay the price of the iPad for a pressure-sensitive pen for it.

Can anyone identify the drawing app he was using to demo?

That's my app, Brushes - iPad Edition:

http://itunes.apple.com/us/app/id363590649?mt=8