What is a fanlisting?
A fanlisting is simply an online listing of fans of a subject, in this case, of an a realtionship of Spock and Nyota Uhura. Joining a fanlisting is free and open for everyone from around the world. The only requirements are your name, your country and a valid e-mail. Usually a fanlisting is a rather small site - it's rather a place to get together with other fans and show that you're a part of fandom.
thefanlistings.org (aka The Fanlistings Network or TFL) is the original (but not the only one) web directory for fanlistings. It lists fanlistings approved by TFL staff, sorted by categories.