It's funny that I say this, but after about the 10th booth showcasing 40 Gb/s technology, the technology suddenly seems old-hat (didn't think I'd ever say that).
Here's something that isn't networking related, but will probably set you back about as much in cash : )
It's an 8 megapixel projector being used at the Sgi booth. They were running some graphics simulations on the projector screen where they would manipulate in real-time some big 3D shapes. In theory it doesn't sound spectacular I guess, but the technology behind it was definitely cool.
The projector has 4 video inputs on it. It shoots the image at a first mirror which then reflects the image back behind and over the projector to a larger mirror. That mirror then reflects the image onto the projector screen which you get to see. The image is shown through the screen; see the pictures.
All this happiness is driven by this rack of systems. I was told that it's not a terrible technical burden, but the rack was just as cool to see as the projector and the equipment behind that.
Behind the scenes access to cool setups is appreciated.