NEW YORK (Reuters) - Frank Quattrone, a former banker famous for taking hot technology companies public, was found guilty on Monday of obstructing federal investigations into some of the most popular stock offerings of the 1990s. Jurors delivered their verdict after deliberating about seven hours over two days, concluding the ex-banker tried to block grand jury and regulatory investigations by forwarding an e-mail to co-workers reminding them to "clean up" their files. It was the second trial for Quattrone, 48, who will likely face one to two years in prison at his sentencing, set for Sept. 8. The first trial...