Brian Williams, Katie Couric and Diane Sawyer -- the big three in network news -- are teaming up once again for a good cause. The trio will join forces for a second Stand Up to Cancer fundraiser. The telecast, which raises money for cancer research, is set for September 10. The announcement was made this morning during the big three networks' morning shows, 'The Early Show' (CBS), 'Today' (NBC) and 'Good Morning America' (ABC).