Foriegn Postage Stamp Bureaus
Send off a request in the victims name to numerous foriegn postage stamp bureaus requesting ordering information, to be put on mailing lists, etc. The response is quite astounding.

Change Of Address
Get change of address cards from the post office and change the victim's address to someplace like Guam.

A Camping Prank
Bury someone's hatchet or ax in a tree about 20 feet off the ground and in plain sight.

Bug Spray Camping Prank
Spray someone's tent with some aerosol based bug spray. This will erode the waterproofing of the tent.

Audio Cassette Prank
Crack open someone's audio cassettes and flip the tape over so that what comes out is pure gibberish

Video Store Swap
Rent porn tapes from the video store and record something like Barney or the Wizard of Oz over them. Just imagine the next person who gets them. Better yet, do it the other way around or exchange the tape in their respective cases. (they aren't likely to check)

The TV Scramble Prank
Take a transciever like the ones ham radio operators use (3 watts or more is good) and push transmit while near a TV. Will have the effect of semi-scrambling whatever is showing. The more powerful the transceiver, the more the TV signal gets messed up. This does work on cable TV.

Disassembled Furniture
Leave someone's furniture in a 99% disassembled state.

Hosed
Tie a rubberband around the pullout hose lever thats in your sink. Whoever uses the sink next will get hosed with water.

Soap In The Hose
Pour some detergent down inside the garden hose. The next time your victim goes outside to water plants or grass. There will be a soapy mess everywhere.