To add different hosts so you can run more than 1 web site.

Install this. http://clickontyler.com/virtualhostx/

Vitualhostx will create the hosts file and reconfigure your builtin Apache.Then in VirtualHostx > file > Run setup wizard. Step 1, step 2.  This configures your Apache install.

Create a new site. eg mysupertest.site and select the folder for this site.

You will need to allow access to the folder, so in the big blox add this. Make sure you change johnb to your name. Or just copy the text above and now you will not get 403 errors.

<Directory “/Users/johnb/Sites/mytest/”>  AllowOverride all
Allow from all
Order allow,deny   
</Directory>

Finally, File > Apply Changes to Server.

Now you can type in your browser mysupertest.site and it will work. Lovely.

If you are curious how it configures you vhost, then run this command from the terminal, it assumes you have textmate installed on your system.

mate /etc/apache2/extra/httpd-vhosts.conf