The quick and dirty is that the watch syncs with your Android or iPhone via Bluetooth, and runs a number of apps that allow you to keep time, control your music, etc. The possibilities are really limitless on this, and with it using ePaper (which is what the Kindle and Nook use), the battery life (USB chargeable, naturally) is about a week. That's incredible, and with the amount of money they've raised so far, it's not scratch/shatter resistant and waterproof.
My watch finally died on me last fall, and I've been resistant to get a new one. This might be changing my mind, because the idea is so neat, the technology feels so advanced - it's almost like what I pictured the future to really be like. I love it.