When the button on my Nike Fuelband broke, I eventually decided to get a Pebble and run the Misfit app on it to track steps. I've also loaded Tetris onto it and the Swarm check-in app. I also get notifications from my phone, via bluetooth.
With a little bit of C, it also seems quite easy to create your own apps or watch faces:

With a little bit of C, it also seems quite easy to create your own apps or watch faces:
