Years ago I stopped at a service station in the UK. Above the urinal I chose to use was a poster advertising a helpline for men experiencing erectile problems. It was called something like "Man Matters". At the base of the poster was a thick booklet of paper slips, each with a telephone number and "Man Matters" and a sentence like "Having erection problems? Call this number." The idea was to rip off one of the bits of paper if you had a problem.
I thought it would be hilarious to take the full booklet, maybe 50 slips of paper in total, then plant individual slips of paper into the pockets and bags of male friends and enemies. This means that when they got round to taking something out of their pocket, the slip of paper would fall out too, and the person they were talking to at the time would read the slip of paper, and laugh at them.
However, after taking the entire pad, I dropped it into my bag... only to completely forget about it myself. Skip forward about a week and I was going though my bag, found the pad of paper, and held it up thinking "What the hell is this?" My housemate at the time asked "What the hell is that?" So I showed him, and explained that I took them as a joke, and explained my plan, and that it wasn't because I had any erection problems myself. I kept the pad though, planning to play the joke on somebody in the future.
It is now probably nine years into that future, and I STILL have that pad of erection problem helpline slips. I've lost it and re-found it many times, and I've yet to actually remember to play the joke on anyone. But other people have found the pad on many occasions, including two girlfriends. I always explain my master practical joke plan, and the other person always nods sceptically, and I always forget about it until the next time. I just went looking for the pad now, to take a photo, but can't find it. I bet I do find it, but only when my next serious girlfriend moves in to the apartment...
Comments
Also, if you really want to do a practical joke along these lines, you can design and print your own pad of something much funnier. Fake winning lottery tickets are a good start. Also, fake receipts from hilarious products and establishments. Oh, why is there a receipt for 100 anal beads from Giggles Inc.?
^_~