Today on TV

NFL (6:30 p.m., ESPN): Steelers at Redskins

Big Bang Theory (7 p.m., Ch. 2): A grad student pursues Sheldon.

Dancing With the Stars (7 p.m., Ch. 4): The contestants perform.

Terminator: Sarah Connor Chronicles (7 p.m., Ch. 13): A Terminator gets dangerously close to John.

How I Met Your Mother (7:30 p.m., Ch. 2): Ted runs into someone from his past.

Saturday Night Live Presidential Bash 2008 (8 p.m., Ch. 5): A collection of political sketches from past shows.

NBA (8:30 p.m., FSN): Jazz at Clippers

CSI: Miami (9 p.m., Ch. 2): A crane crashes into a high rise.