The United Arab Emirates announced this weekend that all BlackBerry mobile services will be banned beginning in October, forcing users of the smartphone to find other ways to surf the web and send email and text messages. The decision will not only affect the U.A.E.'s half-million BlackBerry users, but also international visitors--which could lead to business travelers going into abrupt "crackberry" withdrawal as soon as they hit the Dubai airport. The reason for the ban: