Fixing incorrect posters
The latest idea of some astronomers was to say "Pluto's no longer a planet". Now while this annoyed exam boards (yay!), it also annoyed physics teachers (that's bad!). And it happened to void every textbook and free Guardian poster in the school.
But help is at hand. Grab a Post-It note, scribble "Not a planet!" and an arrow on it and stick it onto a solar system poster to emphasise the fact that Pluto isn't a planet and, in a shock break of Temple Moor tradition, the school is wrong.
Stick to the science men!