Originally Posted by Superterrorizer

Why not ask your host to do it? Some pretty trivial mod_rewrite rules will take care of that.

Originally Posted by Fris

make sure to setup the * entry in your httpd.conf

servername www.domain.com
serveralias *.domain.com

htaccess would be

Options +FollowSymLinks
RewriteEngine On

# mod_dir fix
RewriteCond %{HTTP_HOST} !^(www\.)?domain\.com$ [NC]
RewriteCond %{HTTP_HOST} ^(.*\.)?([^\.]+)\.domain\.com$ [NC]
RewriteCond %{DOCUMENT_ROOT}/subs/%2%{REQUEST_URI}/ -d
RewriteRule [^/]$ http://%2.domain.com%{REQUEST_URI}/ [R=301,L]

# strip sub subdomains
RewriteCond %{HTTP_HOST} ^.*\.([^\.]+\.domain\.com)$ [NC]
RewriteRule ^(.*)$ http://%1/$1 [R=301,L]

# abc.domain.com/def --> /subs/abc/def
RewriteCond %{ENV:REDIRECT_STATUS} ^$
RewriteCond %{HTTP_HOST} !^(www\.)?domain\.com$ [NC]
RewriteCond %{HTTP_HOST} ^([^\.]+)\.domain\.com$ [NC]
RewriteCond %{DOCUMENT_ROOT}/subs/%1/ -d
RewriteRule ^(.*)$ /subs/%1/$1 [QSA,L]

so domain.com/subs would contain all your subdomains

so domain.com/subs/fuck --> fuck.domain.com