It is better to put the alternative hosts in their own <VirtualHost> block if you are going to use mod_rewrite with them. Otherwise, you get the performance hit of mod_rewrite with every hit on the "real" site.

<VirtualHost 123.123.123.123>
ServerName foo.com
ServerAlias www.foo.com
...
</VirtualHost>
<VirtualHost 123.123.123.123>
ServerName other.foo.com
ServerAlias bar.com
ServerAlias www.bar.com
ServerAlias quux.com
ServerAlias www.quux.com
...
RewriteEngine on
# RewriteCond not necessary anymore
RewriteRule ...
</VirtualHost>
[download]

That said, I must say that I hate typing in all those domains and prefer wildcards, when possible :)

Juerd # { site => 'juerd.nl', plp_site => 'plp.juerd.nl', do_not_use => 'spamtrap' }