What is your choice for "GADGET of the DECADE"? (gadget must be released between 2000 and 2009)

This would include electronic devices (ex: ipod, netbooks), web sites (ex: google, wiki), software (ex: windows-xp), games consoles (ex: wii), service (ex:3G, internet broadband, free wifi), etc

If you have to choose just ONE, which would it be and why?