So, the Acquians have been hard at work setting up a big cluster of Solr servers in the cloud to get ready for the big launch of Acquia Search. It's cool because they do all of the heavy lifting and Solr maintenance for you. Drupal search is meh, ok but Solr search is insanely fast and relevant. Your site sends an index (securely) to the Acquia servers, then all of your site queries go (securely) to the Acquia servers to retrieve results.
It's even complete with Drupal access API integration. If you are running the Node Access module, or Organic Groups, it will respect your node permissions!
Drupal.org just switched over to it and people are finally using the site search instead of Google - that's saying something! :)