An interesting experiment - or perhaps it is merely an optical illusion - has been circulating around the internet and cultivating an interesting discussion surrounding the nature of time. Try it here.

Therein, one stares at a clock, any old-school big-hand / little-hand / second-hand style will work. Without too much practice, one can observe that the second-hand becomes "sticky". It will literally stop dead on the clock for several seconds -and this phenomenon has caused quite a bit of reaction and speculation. The best and most cognizant of these theories are summarized in the follow-up post, Why Did Time Stop? Further explorations in tachypsychia, a term used by psychologists to describe the subjective experience of time, can be found below.

• Time out of mind - "We can't touch time, or smell it. Yet it is utterly inescapable. But, research shows, time is - at least partly - something we control in our heads." at BBC News.
• Theory of subjective time perception at Halfbakery.
• We are literally trying to stop time - Wherein track coach John Smith, who teaches the fastest runners in the world how to go even faster, lays down a few helpful practical hints at Fast Company magazine.
• Anybody Really Know What Time Is? - at Wired News.