An expert on the Tyra show said that you can actual use Rogaine for Women on your eyebrows to get them to grow them out.
***(I got this from an article)
If your brows don't grow fast enough, consider Women's Rogaine or men's extra-strength Rogaine applied to the sparse areas with a Q-Tip. According to the September, 2006, issue of Allure, experts recommend applying twice a day for four months. But do a test patch first on your inner wrist to make sure you don't get a rash. Check the patch after a day.
**(from Oprah.com)Eyebrows grow more slowly than other body hair (for which we should probably be grateful), so be patient. But about those bare patches: Zealous plucking or waxing, which repeatedly traumatizes follicles, may result in permanent hair loss, says Katie Rodan, MD, clinical associate professor of dermatology at Stanford University School of Medicine. Try topical 5 percent Rogaine Extra Strength, applied with a Q-tip to the areas where you want regrowth. If the follicles are still viable, you should see results in four to six months. Till then, fill in the gaps with brow gel or pencil (both adhere to the skin better than powder) one shade lighter than your hair color, and blend with an eyebrow brush, says Ramy Gafni, makeup artist and founder of Ramy Beauty Therapy cosmetics.