Just got this in my mind...
When infiltrating a base. You come up with a door that is locked with a code and you donÂ't have explosives to blow it open. So... The code must be broken... I think it would be like 3-5 numbers and a dialog which would look like this...
--------------------------
Code:1**4*
789
456 OK
123
0
(the buttons)
Found numbers:1,4,
--------------------------
When the code is broken the door (or whatever) opens up... Or selfdestruct...