I use Moonshine for automating server configuration and Rails deployment, git aliases for shortening commonly used git commands, and zsh aliases for shortening things like "cd ~/wiki; soywiki" to "wiki".

I also spent a few bucks on an 8 GB RAM upgrade so I could just set MySQL, Postgres, MongoDB, and Redis to run on startup and not have to stop and start them whenever I am working on different apps, and I still have plenty of RAM left over for Photoshop, Starcraft II, etc.

I also spend time practicing vim tricks for things that commonly require a bunch of keystrokes, since practicing shortcuts until they become automatic is effectively the same thing as automating the task itself.

There are also a lot of things I don't automate, but it basically boils down to whether or not I use them enough to make it annoying enough to make me want to automate them. For example, I know that it's possible to set up a Rails template that creates a new Rails app with all of the gems, plugins, and configuration that you commonly use, but since I only create new Rails apps once every two weeks or so it's not enough of a pain that I want to spend the time creating the template.