RewriteEngine On
RewriteCond %{HTTP_HOST} ^www.yourdomain.com
RewriteRule (.*) http://yourdomain.com/$1 [R=301,L]

php_value upload_max_filesize 20M
php_value post_max_size 20M
php_value max_execution_time 200
php_value max_input_time 200

php_value memory_limit 256M

RewriteEngine On
RewriteRule ^([a-zA-Z0-9_-]+)$ users.php?user=$1
RewriteRule ^([a-zA-Z0-9_-]+)/$ users.php?user=$1

RewriteEngine On
RewriteRule ^([a-zA-Z0-9_-]+)/([0-9]+)$ users.php?user=$1&page=$2
RewriteRule ^([a-zA-Z0-9_-]+)/([0-9]+)/$ users.php?user=$1&page=$2