Pixel Qi announced the Display Solutions d-screen-Qi10:
Display Solutions AG has developed the d-screen-HYBRID driver board which has been combined with the low power, sunlight readable Pixel Qi 10” screen. This module can be plugged into a laptop (or even some phones) via USB for easy access to a second screen. Even better, you can skip the cables completely and use this second screen via wireless-USB: meaning the data is sent to the screen wirelessly and the screen runs on batteries alone.
The specs on the 10.1-inch LCD: LED backlight, 1024×600, 262K colors, pure reflective mode (64-level grayscale, 3072×600 pixel format). That last bit I don’t get: each sub-pixel is used as a single pixel?
The wireless option is based on DisplayLink technology. There’s also the option of connecting the Pixel Qi display using Ethernet, which I think is really cool. The USB connection draws just 1.5W so no battery or power adapter is required. It would certainly be a cool feature to have tablets be able to connect to notebook PCs and be used as extra displays. Not as versatile as Pixel Qi / Display Solutions, but Air Display, an app for the iPad and iPhone, allows the two gadgets to be used as extra displays. Air Display uses WiFi so anything other than static information will be pushing it.