Multi-Drupal Site, Single Database Navigation Customization

Another way to customize a Drupal site is via its navigation. The menu structure that we will customize is the blocks. The primary links created using the admin/settings feature are shared by each site so they need to be common to each site. You want this to encourage a similar feel between the sites.
You can use the blocks to create custom navigation. To do this, you need to ensure that your taxonomy is set up to let you classify your records for use in one site versus the other, if needed.