I walk silently also. One Saturday afternoon, my wife and I were out and about. We needed to use the restrooms. Where I worked, everyone had keys to the building. Upon entering the parking lot I noticed a fimilar car in the lot. Jim was allways on the internet, in a chat room, or just doing something he wasn't supposed to. He also drank 2+ pots of coffee every day, and smoked like a fiend. I.E. wall bouncer. My wife and I entered the building. Not being quiet or anything, just walking through letting the doors bang shut behind us. We walk into the cad room, Jim is sitting behing the computer typing away. Doesn't notice anything. I bang on his cube and yell "HEY". Jim (about 23, 6'5" and 165#) spins around in his chair, grasps his chest, starts to drool all over himself, his eyes are as big as silver dollars, minor convulsions, and can't catch his breath. My wife and I are laughing, then in the back of my mind, $hit, he is having a heart attack. He starts to speak/stutter, as the tears are rolling down my cheaks, you, you, you, scared the cr cr crap out of me. After he caught his breath, he was begging me not to tell everyone at work about this.
A couple of years ago a friend of mine got married on Dale Hollow Lake (Ky-Tn) on a house boat, there were 4 of them. One morning, bright and early, I was up walking on the top of the house boat. His future father in law was sitting alone watching the sunrise. It was just over the top of the hill when I got on the top deck. I was walking up behind him thinking "I'm going to scare the crap out of him". Different ways were poring through my head. Then Jim came to mind. I didn't want Berl to have a heart attack the day of the wedding, so I just walked past him. He didn't say a word untill later that day. He just about crapped his pants, thought he was the only one awake, and there was a body standing right next to him.
Other things,
Super glue a quarter to tile or marble floors.
Cat, racoon, opossum, or other animal in the mail box or paper box. Birds work excellent for this.
A realistic stuffed animal attached to the top of a R/C car. Put this in a dark area of the garage, shed, or closet. Then send the wife or kids out to get something.
For those of you in the country, bailing wire a house shut. You tie off on the door nob, and run a tight line all around the house, 3 or 4 times.
Attach one of the "life size" condoms to the tail pipe someones car.
I don't think you can do this any more but... The punching balloons (thick balloon with the rubberband attached) used to be made out of latex, and would stretch unbelieveably large. You place this in the front window of the car with the hose attached to it. It allways worked best with two, one in the back, one in the front, and two hoses. Procede to fill the car up with water to the base of the window on the door. Tie off and let sit. Hoping that the flattened tires don't give it away. At this point the owner is forced to "take a bath". If they are lucky the balloons empty out onto the street only. If not, it takes the inside of the car about 3 summer days to dry out.
Just a few,
Steve