Should I hide a key outside?

Question: Do you think it's a good idea to hide a key outside somewhere?

Fourchalk: Don't hide a key outside, somebody might be watching. Instead, remove your key-in-knob locks and replace them with passage sets (no locking ability) and install a deadbolt above them. Now when you shut the door, you will have to physically lock the deadbolt with the key which you have in your hand!