The Shallow EndDon't start by diving into bigger markets-get your product's feet wet by finding a profitable niche.

Inventions are the basis for plenty of companies, frommultimillion-dollar corporations to small, $100,000 businesses.While many inventors shoot for the former, those in the lattercategory are nothing to sneeze at. They can generate a modestannual income, often without hiring any employees, facing stiffcompetition or having to make a significant investment. Forinventors without strong management skills, finding a uniqueproduct in a small target market is often ideal.

Kelly Greene of La Jolla, California, got her inspiration in1992 when she moved into a new apartment. Greene, 42, likedswimming laps for recreation and fitness, but her apartmentcomplex's pool was too small to provide a meaningful workout.She thought the best solution was to create a method to swim inplace.