Jean Mercier of Oostakker, Belgium has this real serious but frankly, real useful obsession.
He runs the Skype Numerology blog, a resource dedicated to the evolving and statistically quantifiable aspects of Skype's download, usage, and related metrics over time.
Yesterday Jean figured out that last week, Skype attained 10 million concurrent users at the same time. And this week, that number went as high as 10,270,000 concurrents.
Jean thinks the Skype mashup with MySpace could be having an effect.
Me? That's probably a bit too early- more like natural growth of the Skype user base.