History Lesson: The First 5 Users On Facebook
The method for finding out who was the first 5 was simply to play with the id in the URL. You can see that Mark has id=4. 1,2,3 do not exist. The next 2 after Mark are his official co-founders.
Arie, id 7, is the first one who is not a co-founder (officially) . Which makes him actually the first user on Facebook. He’s a Jewish guy that studied with Mark in Harvard and later on did Aliyah to Israel. Last but not least is Marcel who seem to still be working on facebook as a developer.
1. Mark Zuckerberg: http://www.facebook.com/profile.php?id=4

2. Chris Hughes http://www.facebook.com/profile.php?id=5

3. Dustin Moskovitz: http://www.facebook.com/profile.php?id=6

4. Arie Hasit: http://www.facebook.com/profile.php?id=7

5. Marcel Georgés Laverdet II: http://www.facebook.com/profile.php?id=10
