In a recent post to his blog Wojciech Sznapka shows you how to set up your local development environment so that you're not having to configure a VirtualHost (assuming you're using Apache, of course) each time you want to work on a new project.

If you are developing PHP application on your own PC, you probably have some vhost based configuration of your Apache. With some tricks, you can turn your Linux box into powerful development server without configuring vhost for every app. [..] We can ommit two lasts steps [of a typical setup process], limiting preparation of the environment only to place source code somewhere in filesystem. To achieve this we need mod_vhost_alias module for Apache2 and simple DNS server which will resolve local domain names for us.

His tip uses the mod_vhost_alias module for Apache and the dnsmasq tool to make the basic DNS server to resolve these custom domains. A few configuration changes later (included) and you're set to restart apache and be on your way.