(Over) 2 million active geocaches.

As of februari of 2013, the 2 millionth active geocache was placed. Check out the video below to see an impressive animation of the caches that were placed over time and see it spread like a virus.
http://www.youtube.com/watch?v=IfU3blexL7o

Geocaching seems to have started right after the American government ordered an end to "Selective Availability" on GPS on May 2nd, 2000. This would make GPS readers for civilians much more accurate. The switch was flipped at midnight on May 1, 2000 and technology adept Dave Ulmer was
watching his GPS device to see it become more accurate the next second.

Dave started thinking of something to celebrate this important event and thought it would be fun if he would hide some 'stash' for others to find. He filled a bucket with gifts wrapped in plastic and an instruction what to do with it and hid it the next day in the woods outside Portland, Oregon.

Next, he posted this message to a usenet newsgroup:

Newsgroup: sci.geo.satellite-nav
 From: Dave
 Date: 2000/05/03
 Subject: GPS Stash Hunt... Stash #1 is there!

Well, I did it, created the first stash hunt stash and here are
 the coordinates:

N 45 17.460
 W122 24.800

Lots of goodies for the finders. Look for a black plastic bucket
 buried most of the way in the ground. Take some stuff, leave
 some stuff! Record it all in the log book. Have Fun!

Stash contians: Delorme Topo USA software, videos, books, food,
 money, and a slingshot!

The stash was found within a day and the initiative was followed by more hidden stashes. As said, we have 2 million active caches worldwide.

You can listen to Dave's story on podcacher show 409: http://www.podcacher.com/2013/02/show-409-0-dave-ulmer-reminisces/
For original footage of the bucket he hid, see: http://www.youtube.com/watch?v=LMHZcgM11GU
The first month of geocaching in day-to-day posts: http://www.guysnamedkim.com/geocache/geocache_history.html