I've begun working a lot more with Drupal multisites, as doing so saves a lot of time in certain situations (usually, when you have a large group of sites that use the same kinds of Drupal modules, but need to have separate databases and front-end information.
One problem I've finally overcome is the use of actual domain host names for development (i.e. typing in dev.example.com instead of localhost to get to a site). This is important when doing multisite work, as it lets you use Drupal's built-in multisite capabilities without having to hack your way around using the http://localhost/ url.
Here's what I did to use dev.example.com to access a dev.example.com multisite in a Drupal installation using MAMP (the dev.example.com folder is located within Drupal's /sites/ folder):