<VirtualHost 127.0.0.1>
ServerName yourdomain.local
DocumentRoot /Users/yourname/Sites/path/to/public_html/
<Directory /Users/yourname/Sites/path/to/public_html/>
Options ExecCGI FollowSymLinks
AddHandler cgi-script .cgi
AllowOverride all
Order allow,deny
Allow from all
</Directory>
</VirtualHost>
change yourname and yourdomain to what is appropriate, and you should be all set.
be advised that the permissions are pretty loose. (Allow* all) But it's a local site, so that ought to be ok.