I wanted a simple count of the amount of users so I created this block function which displays "Total Members: #".
Place the following in your lib-custom.php
Text Formatted Code
function phpblock_usercount(){
GLOBAL $_TABLES, $_USER;
$result = mysql_query( "SELECT * FROM {$_TABLES["users"]} WHERE uid <> '0' ");
$usercount = mysql_num_rows($result);
$return = "Total Members: ";
$return .= $usercount;
return $return;
}
Then create the php block phpblock_usercount you can call it what you want I called it Members.