Iranians could call abroad on mobile phones Tuesday for the first time since communications were halted during a crackdown on nationwide protests in which activists said at least 646 people have been killed.Several people in Tehran were able to call The Associated Press and speak to a journalist there. The AP bureau in Dubai, United Arab Emirates, was unable to call those numbers back. The witnesses said SMS text messaging still was down and that internet users in Iran could connect to government-approved websites locally but nothing abroad.The witnesses gave a brief glimpse into life on the streets of the Iranian capital over the...