BlueLife KeyFreeze - FREE Windows application that blocks your keyboard and mouse without “locking” the screen.
Transparent Screen Lock - Password protect your workstation or server with "Transparent Screen Lock" while monitoring programs that are running.
Keyboard and Mouse Locker - Lock Keyboard and Mouse!
ClearLock - A transparent screen locker.
VBLock - Converged Infrastructure
LiteLockr - LiteLockr is a free, portable utility for locking your keyboard and mouse.