Fashion designer Zac Posen grew up in New York City. At 16, he interned at the Metropolitan Museum's Costume Institute and with Nicole Miller. Zac's designs have been worn by numerous Hollywood celebrities, including Felicity Huffman, Natalie Portman, and Gwyneth Paltrow. In 2004, he was awarded the CFDA Swarovski-Perry Ellis Award for Ready-to-Wear after his first major runway show. Today, Zac is here to share his collection and to make the perfect New York-Style Cheesecake.

Chef Andre Soltner, currently a dean of classic studies at the esteemed French Culinary Institute in New York City, is a venerable legend in the culinary world. He was the top toque at Lutece restaurant for 34 years, a four-star establishment that defined French cooking in the U.S. He is here today to make a delicious Lamb Stew with Young Vegetables that's the perfect warm-weather dish.

On September 8, 2006, Anousheh Ansari captured headlines around the world when she became the first female private space explorer. This was a lifelong dream for her. She has served as the cofounder and chairperson of Prodea Systems and Telecom Technologies, Inc. She earned a bachelor's degree in electronics and computer engineering from George Mason University and a master's degree in electrical engineering from George Washington University. She is currently working toward a master's degree in astronomy from Swinburne University. Today, Anousheh is here to talk about her experiences on the International Space Station, a trip that Martha's friend Charles Simonyi also undertook.

Opened on April 1, 1990, Doggie-Drive-Thru offers handmade and preservative-free biscuits, holistic food, natural accessories, and dog sitting services, all through a drive-through window. It began as a homemade 4-by-4-foot kiosk (with a $100 budget) and later expanded to a 1,500-square-foot building with annual revenues of $150,000. Doggie-Drive-Thru has two locations -- in Niles and Granger, Michigan. To purchase the biscuits seen on today's show, visit www.thirstypetwaterbottle.com.