In his honor, I am organizing a special memorial "blog-a-thon" among Sagan's fans throughout the blogosphere. If you're a Sagan fan with a blog, you can participate by posting something related to him on or near that date. Read or reread a Sagan book and review it; discuss cool things that you've done that's been influenced by him; pontificate on one of the many topics he treated (SETI, astronomy, critical thinking, the history of science, human intelligence....), or post about something completely surprising.
This effort is endorsed by Sagan's son, author Nick Sagan. I will be participating; Carl Sagan ranks on my list of personal heroes and influences with Hector Berlioz, JRR Tolkien, George Lucas, Sergei Rachmaninov, and any of the other luminaries on whose behalf I have waxed poetic in this space. And if any of my readers are of similar mind regarding Carl Sagan, feel free to join in on posting on the 20th.