[link|http://www.apacheweek.com/features/vhost|Apacheweek - Using Virtual Hosts] has a little information.
[link|http://nebula.worldbank.org/manual/vhosts/|World Bank VHosts Manual] !
But perhaps this Usenet [link|http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&oe=UTF-8&safe=off&th=b9b3cb103ab67a2&rnum=4|thread] is more useful.
HTH.
Cheers,
Scott.
(Who's just trying to save you some Googling...)