Doug Hartwell has always been a tinkerer. When he was a kid, he sewed his own backpacks for hiking. Now that he has a kid — 5-year-old daughter Bella — he's gone into the child-carrier business. In April, the Vergennes resident quit his 15-year career in the defense industry to launch Bitybean, a sleek fabric carrier that rolls up small enough to fit in your pocket. Created with the help of Huntington resident and technical soft-goods design expert Jim Sadler, the highly portable carrier is built for infants and children weighing 8 to 40 pounds, which corresponds to ages 6 months to 3 years old. At half the size of its closest competitor, Bitybean is handy in airports, farmers markets and in-a-pinch, on-the-go situations in which lugging around a hefty stroller isn't a practical option, says Hartwell. The Juvenile Products Manufacturers Association agrees: In October, the internationally recognized organization honored Bitybean with a 2012 Innovation Award. Look for the carriers in stores in late January or early February.