Pope Benedict XVI took to his popemobile after meeting with President Bush at the White House this morning. The pontiff, who is celebrating his 81st birthday today, rode west beginning around noon on Pennsylvania Ave. through Washington Circle before heading north on Rock Creek Parkway before exiting at Massachusetts Ave. to arrive at the Vatican embassy. A large, enthusiastic crowd of about 10,000 gathered to cheer on the Pope as he rode by, rather swiftly......