Are there any Monty Python fans in your group? Here's some stuff that I remember from a module based on Monty Python and the Holy Grail published somewhere years ago. Some of these were meant to be written on paper and rolled up in "scrolls" that players could open and read:
And now for something completely different: The PCs are instantly transported to another totally different adventure.
Coconuts of speed: A coconut cut in half. By banging the halves together to make a sound like a horse galloping, you could increase your speed by some amount. But you get a penalty on charisma roles and it is easy for enemies to hear you coming.
Trojan Rabbit: A large wooden rabbit appears behind the walls of your enemy's lair/castle/whatever. That's all, just a large, empty wooden rabbit with a trap door, but nobody inside it.
Knights who say "Ni!": When you open the scroll (a prop), you read instructions stating that your PC acquires an extreme adversity to hearing a common word like "it" or "the." Whenever your PC hears the word, he cringes and covers his ears, yelling "you have spoken the word we are not allowed to hear!" Of course he can't tell the party what the word is, because to do that he would have to say it.
Brave Sir Robin's Bard: Upon reading a scroll, your own personal bard appears - not the fighting type, just a musician who follows you around constantly and plays songs to accompany your heroic exploits, even when you are trying to be silent, trying to negotiate with someone, etc.
Helm of Taunting: Placing this on the head causes a PC to compulsively taunt his enemies by giving them rasberries, colorfully insulting their mothers, using rude hand gestures etc. - but the PC can do nothing else during combat.
There were more, but I can't remember them now.