SonyEricsson's LiveView is finally shipping in the US - for $82 (it's been available in the UK for quite some time now). The Liveview is an Android accessory with a small (1.3") PMOLED display and can communicate via Android 2.x devices. You can control music, get notifications about phone calls, updates from applications (twitter, facebook) and more. The idea is that you can wear it like a watch.
The LiveView is an interesting device, but it got some dismal reviews from both Engadget and Slashgear who were disappointed - mainly with the buggy software and compatibility issues.