dotfiles.org is a site that collects dotfiles for various shells and editors. If you've ever read someone else's .bashrc and said "Oh, THAT'S a cool trick", this is the site for you. If you haven't, now's the time to start. If you don't know what a dotfile is, or haven't modified the dotfile for your editor and shell, now is definitely the time to start.
Popular dotfiles include: