Some jokes never get old, and one of them can be executed very well using the following project by Instructables user "xbacon". They've documented a very cheap method of creating a device that creates the opposite of a remote-control signal. This can be hidden near (for example) a television, so when someone tries to turn the set off it stays on, and vice-versa - or you could add a delay so the set turns off, then turns back on again after a minute or two.
A project that's sure to annoy, or from a more positive angle - teach the builder more about working with infra-red transmitters and receivers with an Arduino. Either way, visit the Instructable to learn how. And for more, we're on twitter and Google+, so follow us for news and product updates as well.
When adding your own external circuitry to work with your Arduino or compatible board - consider our range of ProtoShields. From the tiny LeoStick to the Mega range, we offer a complete range for you to work with.