Sometimes it seems as though you can turn almost anything into a business. Tracey Moore has done it with practical jokes, creating a company called The Joke's On You! Inc. For $150, Moore will arrange to have a secretary create havoc in your colleague's office, or have him served at his favorite restaurant by a waitress who knows the most intimate details of his life. Her clients? "We get a lot of Wall Street brokers," she says. Somehow that figures.

-- Leslie Brokaw