Would it shock you to learn that the BlackBerry is so addictive it’s earned the nickname “CrackBerry”? Mark Guilbert, vice president of corporate marketing for BlackBerry maker Research in Motion, says it is especially suited to “a Type A person who wants to be in the loop as fast as possible. It’s very satisfying to be able to answer your emails while waiting for an elevator or standing in line for a taxi.” But staying in the loop can take a physical toll: Doctors are seeing some increase in tendinitis and carpal tunnel syndrome among users. The condition even has a name: BlackBerry Thumb.