[TeMPOraL]

Pebble is great for that. They went for e-paper-like screen and buttons instead of backlit screens and touch, and you can easily pull 5+ days of battery life while having it work as an actual watch (i.e. screen always on = time always visible).

Myself, I don't mind multiple devices but not each with a single feature. I would also like them displaying things through the watch, and not just the phone.