It would be very usefull to allow the host block to be selectable by a name 
proerty using regular experssions.  That way an entire class of host names can 
be mapped to a virtual server.  For instance in my example below, this Host 
section is selected if we have all of these:

m1.mydomain.com
site1.m1.mydomain.com
site2.m1.mydomain.com
m2.mydomain.com
site1.m2.mydomain.com
site2.m2.mydomain.com

See below for config.  

===================================

      <Host name="*.m1.mydomain.com" debug="2" appBase="d:/http/my_content" 
              unpackWARs="true">
          <alias>m1.mydomain.com</alias>
          <alias>*.m2.mydomain.com</alias>
          <aliasm2.mydomain.com</alias>
           
        <!-- Context -->
		<Context path="" docBase="d:/http/my_contentden"   
             reloadable="true" crossContext="true" debug="2"/>	
      </Host>

========================

We host as many as 500 virtual sites on a server and need this so we can map 
all sites to the same content area, and add them without changing the 
server.properties file.  The application looks at the host request header value 
to make the final determination on how to treat the content.

Gene Engelgau