Ya I have a good one. I'm not sure I'll explain it properly though.
I was taking a piss at school in the urinal with a friend of mine beside me. Those urinals had the little mothballs in them (small white deoderizers). So I start making conversation with my friend and I take a Menthos out of my pocket and pretend to withdraw it from the urinal (so he thinks its a mothball). And I'm like "yo, what is this thing??" and the kid is just like "aww man, wtf?". So I continue to look all confused with the menthos in my hand and my friend is just staring at me in total disgust when I pop it in my mouth. The kid went crazy he just started yelling and laughing and he was so confused. It was my finest hour. I never thought it woulda worked.