Dynamic subdomains for profiles

Task: Dynamic subdomains for profile pages (or any other similar /xxx/yyy/zzz)
http://vanillaforums.org/profile/mark =>
http://mark.vanillaforums.org/
Also: Apache, mod_rewrite, configured DNS (any request to *.site.com points to the same IP as site.com).

Problems:
1. Cannot think mod_rewrite rule.
2. Canonical URL: mark.vanillaforums.org/profile/mark <--- incorrect! correct is vanillaforums.org/profile/mark<br />Possible issue 479 is related to this problem

Question: no question, just wonder to discuss.

Lincoln

<VirtualHost *:80>
ServerName yoursite.com
DocumentRoot /path/to/docroot
ErrorLog /path/to/logs/yoursite
RewriteEngine On
RewriteCond %{HTTP_HOST} !^yoursite\.com$ [NC] # Has subdomain
RewriteCond %{HTTP_HOST} !^www\.yoursite\.com$ [NC] # Not www
RewriteRule ^(.*)\.yoursite\.com$ /profile/$1 [PT,L] # Silent redirect
RewriteCond %{HTTP_HOST} !^yoursite\.com$ [NC] # Has subdomain
RewriteCond %{HTTP_HOST} !^www\.yoursite\.com$ [NC] # Not www
RewriteRule ^(.*)\.yoursite\.com(.*) yoursite\.com/$2 [L] # Redirect if not profile
</VirtualHost>

Untested! Just my Monday-morning conjecture :)