.htaccess

<IfModule mod_rewrite.c>
Options +FollowSymLinks +ExecCGI
RewriteEngine On
RewriteBase /

# no-www.org
RewriteCond %{HTTP_HOST} ^www\.twivatar\.org$ [NC]
RewriteRule ^(.*)$ http://twivatar.org/$1 [R=301,L]

# if the file or directory does exist
RewriteCond %{REQUEST_FILENAME} -d [OR]
RewriteCond %{REQUEST_FILENAME} -f
RewriteRule .* - [L]

# handle early adopters until they've had time to change their site
RewriteCond %{HTTP_REFERER} ^http://(www\.)?joshrussell\.com\/.*$ [NC,OR]
RewriteCond %{HTTP_REFERER} ^http://(www\.)?twaud\.io\/.*$ [NC,OR]
RewriteCond %{HTTP_REFERER} ^http://zubeta\.com/.*$ [NC,OR]
RewriteCond %{HTTP_REFERER} ^http://blog\.petrusha\.name/.*$ [NC,OR]
RewriteCond %{HTTP_REFERER} ^http://offline\.twivatar\.org\/.*$ [NC]
RewriteRule ^(mini|bigger|normal|original)/([a-z0-9_]*)/*$ index.php?size=$1&user=$2 [NC,L]

# NOTE valid usernames are: Only use letters, numbers and '_'
RewriteRule ^([a-z0-9_]*)/(mini|bigger|normal|original)/*$ index.php?size=$2&user=$1 [NC,L]
RewriteRule ^([a-z0-9_]*)/*$ index.php?user=$1 [NC,L]
</IfModule>