According to Movable Type, this is entry number 250 for PhysicsStop. A quarter of the way to one thousand entries. Has anyone read them all? Now, according to the statistics I get to see every month, the single most looked at entry by far is this one, on The3is in Three. Why is it so popular? I have no idea.
In recent times, the second most looked-at entry has been the joint Seccombe/Wilson family effort on Fallstreak cloud.

Why is it so popular?
It’ll most likely be because Nat promoted it:
http://radar.oreilly.com/2009/10/four-short-links-30-october-20.html
In my experience, the most visited articles are invariably a consequence of others’ promoting them, esp. sites that get a lot of traffic, as the O’Reilly site does, or twitterers that have a lot of followers, etc.