Cellular telephones and wireless BlackBerry email devices may be addictive, but most business executives insist that <A HREF="http://news.zdnet.com/2100-1035_22-6109624.html?tag=nl.r23660">mobile technology has improved the balance</A> between their work and home, a study said Thursday. The study, by executive recruitment firm Korn/Ferry International, found that four out of five executives globally are always connected to work through mobile devices, such as cell phones, PDAs, laptops or pagers. More than a third of 2,300 executives surveyed in 75 countries believed that they spent too much time connected to communications devices.