The Great Throwdini; Freeport, N.Y.; knifethrower.com

Ten years ago, The Great Throwdini (David Adamovich), now 59, retired as a physiology professor, bought a billiard hall and took up knife throwing. Adamovich now holds six world records and performs about 20 solo shows a year. He has performed on Broadway, at corporate events and weddings and on TV shows such as "Late Show with David Letterman" and ESPN's "Cold Pizza."

He makes around $100,000 a year for his knife-related ventures, but for $75 an hour Adamovich also offers private lessons at his Long Island, N.Y. home. (If you don't want to make the trip to Long Island, he sells an instructional DVD.) The knives, which look more like knife shapes cut from cheap stainless steel, are surprisingly heavy but blunt and aren't sharp enough to puncture the skin. (In ten years, using knives of all shapes, sizes and degrees of sharpness, Adamovich has never drawn blood.) --Maggie Overfelt