There is some great fic on Andromeda Uncovered (http://www.andromedauncovered.com/index.php), which is Mary Avatar's emporium of crack and smut.

And, in interest of tooting my own horn:

I have a very small, very quiet community called andromedafix which is a place to talk about the show, and rec and post fics. I also have links to various author sites.

I have an even smaller stargate/andromeda crossover community, where I have post season five Harper ending up in mid season one Atlantis in andromedagate