Always running out of space on your Nexus One phone's display?
Wish you could see who was texting you or know the current time when you're playing full-screen games?
You need a dual-screen Nexus One:
The project hardware includes an Arduino, USB Host Shield, LCD display and a Nexus One phone running Android 2.3.4.
The LCD display accessory is implemented using the Android Open Accessory Protocol (like the ADK): an invisible background service is started automatically when you connect the accessory. The service displays a notification of the accessory found, listens for new text messages and starts sending the current time to the accessory for display. You can use your phone as normal while the service is running in the background.
More details, source and photos on my Labradoc project log.
P.S. If you want to get started with creating Android accessories but don't know how to write Android code check out my post on Handbag
it's the easy way to get started without writing Android code.