Want a chance to introduce Bruce Springsteen? You'll have to act fast - and be able to do four hours of volunteer work today for Barack Obama in Pennsylvania. That's just one of the latest bits of news about this "little" event on the Parkway tomorrow afternoon. You've probably heard about it: Free Springsteen concert. Gigantic crowd expected. Gates open at 2 p.m. Event at 3:30 p.m. It's also an Obama rally that hopes to boost voter registration before Monday's deadline in Pennsylvania, and recruit more volunteers.