The *Stolen* PE Kit
A slight variation of 'I lost my kit':
1) Hide your PE kit in a less-than-obvious place at school
2) When the PE lesson starts, tell your teacher about the *stolen* kit
3) Ask if you can look for it
4) Turn up 10 mins before the lesson ends with kit in hand, and abracadraba you don't need to do it
5) Particulary convincing if you are of the 'geeky' type, because no-one suspects a thing.
(Unless your teacher is really evil)
* May I add all of these are copied at your own risk and I am no way responsible if you risk tarnishing your educational record...