Mac OS - Open Terminal
sudo nano sublime
Then paste the code from the gist into the file. Then hit ctrl+x and then y to confirm you want to save. After this you will need to make the file executable. Still in the 'usr/local/bin' directory.
chmod +x sublime
Now you can type 'sublime' into the command line and specify a directory of if you don't. It will open the current directory in Sublime Text editor. Enjoy!
***NOTE: This is Sublime Text 3 - if you are going to use Sublime Text 2 - Change "Sublime Text" on line 18 to "Sublime Text 2"