I thought of this in the "Horn" thread, but what are some funny pranks you have done to friends?
When I lived in an appartment complex, I took a 4x8 sheet of ply wood, painted it black, and screwed it to the out side of a neighbors door.
Another time, in keeping with my "horn" theme, I installed a horn behind my friends driver seat. As this was my first "Horn prank" I needed to find a way to get him to hit his horn. After a few weeks, I got him to follow me, I kept driveing slower, and slower until he hit his horn. It scared him so bad, when he jumped in his seat, he knocked his rear veiw mirror off his windshield.
Lets hear yours!