Confetti from the hole punch can be used for so much! My boss was a keen golfer, golf brolly always to hand although rarely used. For about a week I went round the office of about 50 collecting it and putting it my bosses brolly.

He came in the Monday laughing. He was in a tournament on the Saturday and as champion had the honour of teeing off first while everyone watched on. Great shot! Starts drizzling a bit so while the second guy readies himself at the tee my boss opens his brolly and shed loads of the stuff is all over him. The place erupted!

I used to enjoy taping down the wee black bits in phone cradles with clear sellotape then phoning them! Of course the phone just kept on ringing and they were very confused.

Turning computer screens 180 degrees if someone left their computer unlocked and various other settings.

Friends and colleagues leaving unlocked phones set to Japanese or similar.

Yes I am the sort of person that sees a tray of alarm clocks or timers in a shop and thinks ya beauty!