People /used to/ wind their watches every day. I remember having one for years as a kid. Then we invented the battery-powered watch because we realized winding a watch and setting the time every day was a royal pain.

I'd actually be thrilled if Apple started using eInk screens in things, especially something like the iPad Mini. I know they won't too, but if this device is anything like the latest iPod Nano, it /might/ get a few days on one battery charge. Assuming it's real to begin with.