As an attempt to make this interesting (by completely ignoring it):<p>It turns out that, by employing quantum mechanics, it's possible to encode data and then later answer the question "has anyone looked at the data yet"?<p>Let's say you're a secret agent. You get your instructions from shadowy figures in paranoid places. And, being a <i>secret</i> agent, it would obviously be a problem if anyone were to eavesdrop on the instructions sent by your employers. Quantum entanglement allows you to check: has anyone already looked at this message?<p>Pretty neat!