Here's a good brain-teaser from [wu:riddles] —
You're a super-villain and you want to prepare a transparency (the kind that goes on an overhead projector) with the key points of your plan for world domination so you can present them to the hero/superagent before you attempt to kill him in some ridiculously novel way. You don't want this information to fall into the wrong hands before you're ready. Smart villain that you are, you know you can share the information across several slides so that if the enemy agents capture any 2 of your slides, they won't learn even the tiniest bit of information about your plan. How?