Who else writes Bukkit mods? Post about them here!
I wrote
Nomcraft! It is an extremely extensive mod doing things like multi-type multi-worlds, irc connection, pm system, guilds, warps, map rendering (with normal and cave modes), etc etc. I can't even list all the exact features cause I'm still to lazy to actually go through and write them all down
If you want, you can browse the source in the svn to try to get an idea of everything, or download it and try it out! =D