These are ideas to mess with players, mostly in a non-fatal manner. Many of them are links, and are not originial to me.
Groundhog Day - Based upon the movie Groundhog Day. Party finds itself in a small village. They end up repeating the day over and over again. The party has to find what they took from the local dungeon, or changed in the dungeon to break the cycle.
Delaying the Players - Adventurers usually have to travel between adventures.
Disarming the Players -
Looting the Dead - idea on how to control players from becoming rich by just looting the dead.
Material Components and Prices - Manipulate the prices and availibity of spell material components of any spell the party uses a lot of.