INSTALL INSTRUCTIONS
====================
  Assuming you will make all new sites available at /site/{shortname}/
  1. PUT SOMETHING LIKE THIS IN YOUR APACHE CONFIG:
  <VirtualHost *:80>
    AliasMatch ^/site/\w+/(.*) /var/www/drupal/$1
    DocumentRoot /var/www/drupal/
  </VirtualHost>
  WARNING:CLEAN URLS demand a much more complicated setup with a bunch of rewrite rules.
          See the Appendix in this file for details
  
  2. PUT SOMETHING LIKE THIS IN YOUR ./sites/default/settings.php
     or better at ./sites/www.example.com.site/settings.php
  ----CODE BEGIN-----
  $requri = explode('/', request_uri());
  if (sizeof($requri) >1 && $requri[1]=='site' && $requri[2] != '') {
    $my_site_base = $requri[2];  
    #this will be the database shared between the main site and the shared sites
    $db_url = 'mysql://username:password@localhost/database';
    $db_prefix = $my_site_base."_";
    $base_url = "http://www.example.com/site/$my_site_base";  // NO trailing slash!
  }
  ----CODE END-------

  3. Any modules required for profile selections must be installed on
  BOTH the main site's modules directory AND the subsidiary site module 
  directory (a symlink will do just fine);
  the former in order to install, the latter in order to run.

APPENDIX: 
=========
How to get CLEAN URLS working with apache and multisite setup:
   It's gross!  I told you so!!!!!

<VirtualHost *:80>
  DocumentRoot /usr/local/share/sandboxes/common/drupal/drupal/
  # Welcome to the Ugliest Rewrite Rules Evar(tm)!
  # Here's the jist:
  # 1. AliasMatch will set the file context without passing a different URL to Drupal
  #    Therefore index.php must be matched outside of Rewrite rules
  # 2. Rewrite is used ONLY to forward URLs of the form /xxx -> index.php?q=/xxx
  #
  # If we took Rewrite rules outside of the Location contexts so its in per-server
  # processing, we might be able to simplify this.  We would need option 'PT' for
  # passthrough and then some AliasMatch record AFTER the rewrite rules.

  # If you figure it out, then go for it.  Otherwise, what ain't broken...
  AliasMatch ^/site/\w+/index.php /var/www/drupal/index.php
  AliasMatch ^/site/\w+/(modules|misc|files|themes|sites)/(.*)$ /var/www/drupal/$1/$2

  <Location />
    RewriteEngine on 
    RewriteCond %{REQUEST_FILENAME} !-f
    RewriteCond %{REQUEST_FILENAME} !-d
    RewriteRule ^var/www/drupal(.*)$ index.php?q=$1 [L,QSA]
  </Location>
 <Location /site>
    RewriteEngine on 
    RewriteCond %{REQUEST_URI} ^/site/
    RewriteCond %{REQUEST_URI} !index.php
    RewriteCond %{REQUEST_FILENAME} !-f
    RewriteCond %{REQUEST_FILENAME} !-d
    RewriteRule ^/var/www/drupal/site/(\w+)(/)?(.*)$ http://www.example.com/site/$1/index.php?q=$3 [L,QSA]
  </Location>
 
</VirtualHost>