Make Money Satisfying Religious Needs

Orthodox Jews are forbidden to work, write, drive or perform other activities from sundown Friday to sundown Saturday to keep the Sabbath holy. Cooking or fire lighting are not allowed too in the home, including its modern equivalence – the use of electricity.
A bit inconvenient for Orthodox Jews, but there are people who view this inconvenience as a money-making opportunity. One of them is Jonah Ottensoser of Star-K. He earns a living by guiding companies like General Electric, Electrolux, and Viking in building Sabbath-compliant appliances and products. Since he was hired seven years ago, Ottensoser has helped design Sabbath modes for more than 300 types of ovens and stoves, and dozens of refrigerators.
This certainly makes good business sense; in the US alone, there are 900,000 Orthodox Jewish households (and millions throughout the world). Increasingly, tech companies are acknowledging cultural and religious values which would allow them to tap emerging overseas markets as well as become more competitive in domestic niche markets.
Read: The Geek Guide to Kosher Machines [Wired]