added a blurb to the README regarding installing composer via homebrew.

README.md

@@ -48,6 +48,15 @@ in a system wide way.
 3. Change into a project directory `cd /path/to/my/project`
 4. Use composer as you normally would `composer.phar install`
 
+Global installation of composer (via homebrew)
+----------------------------------------------
+
+Homebrew can help you easily keep up-to-date with the latest composer version.
+
+1. run `brew install https://raw.github.com/gist/1574469/composer.rb
+2. Change into a project directory `cd /path/to/my/project`
+3. Use composer as you normally would `composer.phar install`
+
 Configuration
 -------------