When a fire roared through their Palm Coast, Fla., neighborhood in June 1998, Jim and Debby Hodges fled so quickly they had to leave their beloved mutt Elvis behind. But that was before off-duty firefighter John Bartlett, from Jupiter, Fla., sprayed the Hodges' property with his experimental fire-stopping gel. The next morning, they found not only their house untouched by flames but also Elvis's doghouse blessedly intact—with its hunk-a, hunk-a tail-waggin' love safe inside, burning only with gratitude. "That gel," says Jim Hodges, "is the best invention since the fire truck."

Call it a doggone miracle, call it a revolution in fire-fighting technology. But be sure to call it the best invention ever to come from a dirty diaper. Because if Bartlett hadn't picked up the one surviving remnant of a Dumpster fire in 1993, he would never have figured out that the superabsorbent material used in diapers also has a phenomenal ability to repel heat. Bartlett turned the substance into a sprayable goo, which Bill Kramer, a former fire chief who teaches fire science at the University of Cincinnati, calls "a quantum leap in fire fighting."

Now Bartlett, 45, and his partner Bruce Hill, 42, are marketing the product they call Barricade to homeowners and fire departments alike. The duo have yet to make money, but the Los Angeles Fire Department and Indianapolis International Airport are using it, and with the Federal Aviation Administration wanting to study its uses on airplanes, the inventors hope their fire-safe formula leads to smokin' profits. After all, says Bartlett, the married father of one son, "we developed it from the bottom up."