NBC has structured a unique development deal with a comedy duo called the Mommies that will include one-minute prime time vignettes and “Tonight Show” guest appearances in addition to a planned prime time series.NBC exec VP of prime time programs Perry Simon said the multifaceted deal is “an experiment in using all the weapons in a network’s arsenal to more effectively nurture a personality.” The plan is for the Mommies (comics Marilyn Kentz and Caryl Kristensen) to appear in one-minute advice vignettes, make a fourth-quarter appearance on “The Tonight Show” and then quarterly next year leading up to a possible series built around their act, which focuses on being a wife and mother in the ’90s. Simon added that this was a unique situation and didn’t indicate that “Tonight” would become a launch vehicle for the network. NBC Prods. took over production of the late night show last May, when Johnny Carson left and Jay Leno became host. The relatively unknown comedy team was discovered at the Montreal Comedy Festival, and the network is looking for a producer and production company to craft a show around the pair, flying interested parties up to see the Petaluma-based Mommies perform at comedy clubs in Northern California. “To just wait for the acts to come to Hollywood is a mistake,” Simon noted.