This is your brain on e-mail
BlackBerry users are forced to go cold turkey when maker Research in Motion's servers go down for the better part of a day. "I felt like my left arm had been amputated," says one. Six months later a number of prominent addicts - including venture capitalist Fred Wilson and Dilbert cartoonist Scott Adams - admit to experiencing phantom incoming-message vibrations even when not wearing their devices. 
Last updated December 20 2007: 10:06 AM ET
