<?php
$sql = "SELECT n.uid, n.title, n.created FROM {node} n WHERE n.status=1 AND n.type='note'";
$wiki_rev_sql = "SELECT node_revisions.vid AS vid, node_revisions.title AS node_revisions_title, node.nid AS node_nid, node.language AS node_language, users.name AS users_name, users.uid AS users_uid, node_revisions.timestamp AS node_revisions_timestamp FROM node_revisions node_revisions LEFT JOIN node node ON node_revisions.nid = node.nid INNER JOIN users users ON node.uid = users.uid";

$result = db_query($sql);
$wiki_revs = db_query($wiki_rev_sql);
$users = array();

while ($row = db_fetch_array($result) ) {
  $uid = $row["uid"]; 
  $users[$uid]++;
} 

while ($row = db_fetch_array($wiki_revs) ) {
  $uid = $row["users_uid"]; 
  $users[$uid]++;
}

?>

Contributors who have posted:

The following information was updated 6/18/12:
Number of maps created in MapKnitter: ~300
Number of research notes generated: ~825
Total number of users on the site: ~3297 (but many of these are spam)