Dallas entrepreneurs pitch their smart lightbulb; a father-and-son team from Las Vegas demonstrate a high-tech replacement for a cork; parents from Washington, D.C., want money for their subscription-based children's book business; and a Sarasota, Fla., woman has a fort-building kit for kids that costs $199. Also: a follow-up on the company Breathometer, which was invested in by five of the Sharks.