Just saw this on ThinkGeek. Hot stuff. A little pricey though.
* Connects to PDAs Smartphones and Computers using Bluetooth
* Projects a full size keyboard onto any flat surface
* Allows the convinence of regular keyboard typing in a tiny form factor
* Rechargeable battery lasts for 120 minutes of continuous typing
* Tiny size only 3.5 inches high
* Compatible with PalmOS 5, PocketPC 2003, Windows Smartphone, Symbian OS, and Windows 2000/XP. Limited Mac OSX Support.
Although, I’d like it to be embedded, like from this image from QJ.NET.