How can I download code from Github? I'm still running some Drupal 6 sites (because I'm waiting for the Migrate module to work properly in Drupal 8), and I notice that there are some modules in rupal D6 (like Views) which are still bringing out security releases. However, since the code has been moved off drupal.org, these new releases are not getting downloaded by Drush when I do a pm-update to install security releases.

Is there any way to tell Drush to look on Github for certain modules? Alternatively, is there a git command to do this?
The git command is git clone. You would type:

git clone &lt;repository-url&gt; path/to/modules/module_name