How do I do git clone with drush to download the HEAD version of a module?
drush dl views-7.x-3.x --package-handler=git_drupalorg


Update:

True, if there are commits after the dev release was packaged, you will need to run git pull to advance to HEAD after checking out via drush dl.  If there is no packaged dev release, and Drush checks out a stable release, then you need to run git checkout 7.x-3.x after drush dl.

There is no Drush command to do a verbatim git clone; part of the "value add" of drush dl is that it grabs published releases.  If git clone is what you want, perhaps a short bash script would be your best solution.  Something like this:

Usage:

$ clonedev views 3


Example script:

#!/bin/bash

MODULE=$1
VERSION=$2

DRUPAL=$(drush status "Drupal Version" --pipe | sed -e 's/\..*//')
if [ -n $DRUPAL ] ; then
  cd $(drush drupal-directory modules)
else
  DRUPAL=7
fi

git clone --recursive --branch $DRUPAL.x-$VERSION.x http://git.drupal.org/project/$MODULE.git


Modify to suit.