Yes, you can start rosemary from cuttings. The best time is when the plant is in active growth mode in the late spring and early summer, but you can still probably have some success this late in the year. Take cuttings about 3 inches tall from the younger growth on your plants, and dip the cut end into some rooting hormone (you can buy at garden centers). Then, put the cuttings into a flat of moist vermiculite or sterile potting soil. Give them bright light, but don't put them in full sun and keep them just slightly moist. With luck some of your cuttings should root. After the roots are an inch or so long, you can pot them up individually.