Here's a quick tip for people using Mac OS X and like an easy way to install and maintain drush, our beloved Drupal command line tool.
Seems like Homebrew, the so called "missing package manager for OS X", has a Formula (read: package) for Drush. This means that using Homebrew you can install Drush on your Mac using one command:
brew install drush
If you don't know what Homebrew is or does: it's a package manager for OS X which allows you to easily install extra (UNIX) software like drush, solr, wget, varnish on your machine. Kind of what apt-get does on Ubuntu or yum does on CentOS. It's a recently developed alternative to Fink and Macports.