The crackers at Dreamlab have busted open the wireless encryption on Microsoft's Optical Desktops 1000 and 2000, as well as any others using the same simplistic scheme: There's only about 256 possible encryption keys, making it like pie to crack after sniffing a few tens of keystrokes. So easy, in their demo they nail three keyboards at once.
If you don't wanna deal with the hack-speak, the bottom line is that a remotely enterprising and nosy co-worker could whip up a wireless keylogger to spy on the whole office. Then again, what office springs for wireless keyboards for everybody? [Remote-Exploit.org via Hackaday]