This virtual host configuration will automatically choose a directory for the site's document root based on the domain name.
<VirtualHost _default_:8080>
RewriteEngine on
# Remove "www." from domain names by redirecting.
RewriteCond %{HTTP_HOST} ^www\.
RewriteRule ^(.*) %{HTTP_HOST}`$1 [C]
RewriteRule ^www\.([^\_]*)\`(.*)$ http://$1$2 [R=301,L]
# Use components of the domain to determine the document root.
# %0 is the whole domain.
# %1 is the first part (using dotted delimiters).
# %-2 is the second to last part.
ServerAlias *.example.com
UseCanonicalName Off
VirtualDocumentRoot /var/www/html/workspace/%1/htdocs
# Make this configuration compatible with Drupal and Pressflow clean URLs.
<Directory ~ ".*">
RewriteBase /
</Directory>
</VirtualHost>