I'm looking for a keyboard locking software, so that my Windows environment (XP/Vista/7) looks the same (no login/locked screen), but keystrokes have no effect as any input, except for a predefined sequence of strokes (say "unlockme").
What I found so far is a non-free solution. Do you happen to know any free solution?
UPDATE: "looks the same" is a requirement since I'd like to know when I have new emails, or when a long-running task is done. Any login/locked screen hides such information. I'm not away, I'm still around, and so is my son (almost 4 years old!).