Stores now often use a touchpad on top of an LCD screen for entering PINs at the cash register. It should be easy to make an LCD screen that has a small angle of visibility so only the person who stands directly in front of it can read it. Then make the number "buttons" show up on the screen in different order for each user so no bystander can guess the PIN from the points that the user hits on the screen. Perfectly safe.
The number buttons should not be set up on the 3x4 pattern like the keypads on phones. Users would go nuts before their subconscious "unlearns" that pattern. I suggest two rows of five buttons.-- kbecker, Jun 26 2003 PIN Disguise http://www.halfbake...idea/PIN_20Disguise*sigh* [phoenix, Oct 17 2004] View Slot PIN Entry http://www.halfbake...0Slot_20PIN_20Entry*sigh* again. [phoenix, Oct 17 2004] Good for a laugh (+)-- FloridaManatee, Jun 27 2003 You should turn this idea into a game show..."Fingers on the buzzers".....-- skinflaps, Jun 27 2003 This will be a complete nightmare for the visually impaired. (-)-- oneoffdave, Jun 27 2003 I thought this was going to be about babies and nappies.-- po, Jun 27 2003 More trouble/money/time than it is worth, people need to take responsibility for looking around them and sheidling the pad.-- sike, Aug 22 2003 random, halfbakery