my dad was a fun worker too, atleast when he worked at dodge :shrug
he took his bosses calendar, with all the appointments for car tunups oil changes all that. even her personal stuff, he took all of the pages (all 365 of them) and shuffled them, after taking out the binding and such. he took a co-worker's car and swapped the wiring around so the brake was horn, and the wipers were headlights, the whole thing was just messed up