Raymond Niro rarely looks for clients anymore. Instead, the charming, Chicago-based litigator hunts for patents. This unconventional strategy has made him rich and, in some circles anyway, infamous.

The Niro (rhymes with Cairo) technique works like this: In early 2001, he learned that Schneider Automation, Inc., was selling a patent covering the use of spreadsheet programs in manufacturing equipment. The North Andover, Mass.-based company invited hundreds of companies to bid on the patent. No one was interested — except for Niro.