Saturday May 18:The Pro Football Hall of Fame is celebrating Ohio's Bicentennial this weekend. The festitivites kicked off early this morning as a long line of visitors waited for the Hall's doors to open. The day's ceremonies begin with an unveiling of a historical marker followed by the bellcasting ceremony at 1:15. The world's only "foundry on wheels" arrived at the Hall of Fame this morning to prepare for the bellcasting. Hall of Famers Len Dawson and Dan Dierdorf will preside over the ceremony and then sign autographs this afternoon as a part of the Hall's Best of Yesterday and Today celebration.