i really like the following internet experiments, but struggle to find any more. does anyone have any suggestion? or links where i could find more of such experiments..

six degrees of seperation theory:
http://smallworld.columbia.edu/

the pound coin that got too much attention because of ebay:
http://netcetera.org/poundcoin/

"message in a bottle" experiment:
http://www.conwasa.demon.co.uk/bottle.htm

also i have see a site where a guy stamps a message on dollar notes (they email back to him)to track there whereabouts.

many thanks slarter