Hi!
After reading the handbook chapter on Blocks (http://drupal.org/node/17170) and specially this topic about "showing the highest contributers to a site" (http://drupal.org/node/15638), I managed to make this block to show the 10 Personal Image Galleries which have images uploaded most recently:
$users = db_query("SELECT COUNT({image}.nid) AS count, {users}.uid, {users}.name FROM {image} INNER JOIN {node} ON {image}.nid = {node}.nid INNER JOIN {users} ON {node}.uid = {users}.uid WHERE {node}.uid != 0 GROUP BY {users}.uid ORDER BY {node}.created DESC LIMIT 10");
print "<div class=\"item-list\"><ul>";
while ($user = db_fetch_object($users)) {
print "<li>".l($user->name,"image/uid/$user->uid")." ($user->count)</li>";
}
print "</ul></div>";
All you have to do is add a block, set 'input format' to PHP code and paste the code above. Then enable the block.
If you want more than 10 galleries, change 'DESC LIMIT 10' to the desired number.
If your users have personal and non-personal images/photos, you might want to change the where clause to:
'WHERE nyc_node.uid != 0 and nyc_image.personal = 1'
so that only the images assigned as "personal" will be counted.
In my case, I used this patch "show personal images in shared galleries" (http://drupal.org/node/11392) and changed the sql a little bit so that when you see the personal gallery of an user, you see all the images they uploaded.
I hope it's useful. :-)