His life and contributions will be celebrated this November 7th at an all-day event at Florida's Broward College. The program includes teacher workshops, children’s activities, showings of the Cosmos series episodes, food, magic shows, science displays, planetarium programs, telescope workshops, games, door prizes, star-gazing, and (according to their press release) many surprises. Among the scheduled speakers are Phil Plait (creator of the "Bad Astronomy" blog), "the Amazing" James Randi (magician, skeptic and debunker of fake psychics) and David Morrison (senior scientist at the NASA Astrobiology Institute, NASA Ames Research Center, Moffett Field, CA).
The event is co-sponsored by the Carl Sagan Day Planning Committee, Broward College, Center for Inquiry, Florida Atheists and Secular Humanists, and the James Randi Educational Foundation. All activities are free and open to the public. More information and the schedule of events can be found here.