I was blown away by the companies...business model aside (it was a demo event...they didn't have to get into business nuts and bolts and instead simply were asked to make us go 'wow), people were building some really cool stuff.
Building software that allows you to input text using handwriting methods on a QWERTY keypad interface. Sounds weird, but the guy FLEW through the demo and only messed up once or twice...PLUS, what was the most important to me, was that even post mess-up the revision process was FAR better than anything I've ever used.
Next Step: Get 20 18 year old girls in a room, pay them each $20 for an hour and have them text all their friends using the interface. Chart the response. This could be big.