I was reading the "A $22.01 click" thread and everyone know how much was their highest click. How do you know this? Well the 22$ click was catch because it was a lonely click, but is everybody controling their clicks continouly?
Probably not, but if you happen to be logged into a computer with the Firefox adsense plugin installed, it's not hard to see if your earnings go from 1 click/0.30 to 2 clicks/22.31 Though of course, with lots of traffic and clicks, this would be a bit harder...