There is a kickstarter project to make a wrist watch called the Pebble which serves as a secondary screen and input device for a mobile phone or other device. The display is eink so it is low power but also low speed refresh, no idea bout real battery life. I think production is still about a year away but they already have $10M in kickstarter advanced purchases. The kickstarter page also shows it being used as a cycle computer (speedometer/odometer) while the phone presumably is safely buried in a pannier or handlebar bag.
Is anyone considering developing apps to use this device with the N900/N9 or will most people wait for the next great FOSS Linux handheld after the Nokia devices are obsolete. There was work on the first and 1.5 generation devices from Sony Ericson such as the LiveView using existing Maemo apps like OpenWatch.
Kickstarter Page:
http://www.kickstarter.com/projects/...ne-and-android
OpenWatch for N900:
http://talk.maemo.org/showthread.php?t=45333

Pebble can receive simple alerts and notifications from if this then that (ifttt.com) or our web-facing RESTful endpoint. More adventurous developers can use the Pebble SDK, with its Arduino-like abstractions and simple C structure, to gain full control of the watch. Multiple apps can run on Pebble, along side watchfaces and regular notifications.

Load apps using Bluetooth
144 x 168 pixel display black and white e-paper
Bluetooth 2.1+ EDR and 4.0 (Low Energy)
4 buttons
Vibrating motor
3 axis accelerometer with gesture detection
Distribute apps via Pebble watchapp store