(Sep 27, 2006 +0800)
All-time Ranking
1.    allamerican    18929700
2.    jessicapierce    18818800
3.    Ea    13962900
4.    Micio    12456600
5.    Wojtek Kowaluk    10946400

In average, a veteran  player can label about 10 images successful with other unknow player (average player). Sometimes you may label more image. And the highest score I knew was 23. That means if you player a lot, you may label 10 images in about 90s. And it's OK to take 10 images per 100 seconds.

Now let's do some maths:
18929700 means 189297 success labeled images. And it will take the player about
189297 / 10 * 100 = 1892970 seconds. And if "allamerican" is a crazy labeler, and he/she is labeling always. We suppose he/she spend about 12 hours every day in labeling. Let's see how many days it will cost to get such ranking:
1892970 / 3600 / 12 = 43.81875
It means it will take the player more than one and a half months to get such ranking! Is it crazy? Full-time labeling?!

I think "allamerican" is not a player but a group of players! Or some one hacked the rule of Google Image Labeler!