When using drush make on projects where each repository (or module) have their own makefiles and these declares the same modules over and over again drush will download the same data more than once. The code here will utilize drush's cache to only download a module or library once.

You can use drush to synchronize databases and files directories from production servers to your local development setup. This blog post show an easy way to setup these aliases and adds three new commands to do drush synchronization.