Last spring I started working on a Drupal module that would keep CiviCRM contacts in sync with Salsa contacts. I did a lot of the work on it and then, upon joining PTP's staff, the project unfortunately fell to the bottom of my stack.
The code is available...
git clone git://git.mayfirst.org/ptp/civicrm_salsa
... but it's barely code-complete and has had absolutely no testing, so we're not releasing it yet.