What we're watching and why: What is it about "Smallville"? It seems to be on every network at every time. Anyhow, it's on HDNet tonight at 8. But HDNet Movies has Dirty Harry's "Sudden Impact" at 8, followed by "Gladiator" at 10. If that's not enough high-def entertainment, ESPN-HD has a college football game, Central Florida at South Carolina, at 7:30.
Here are some other HDTV programs showing on selected networks today. All times are Eastern:
ABC: Shanghai Knights (8 p.m.)
CBS: CSI: Crime Scene Investigation (9 p.m.), Without a Trace (10 p.m.), Late Show with David Letterman (11:35 p.m.)
NBC: Joey (8 p.m.), Will & Grace (8:30 p.m.), ER (10 p.m.), The Tonight Show with Jay Leno (11:35 p.m.), Conan O'Brien (12:37 p.m.)
Fox: Prison Break (8 p.m.)
WB: Smallville (8 p.m.), Everwood (9 p.m.)
ESPN-HD: BFL Live (4 p.m.), NCAA football: Central Florida at South Carolina (7:30 p.m.), SportsCenter (11 p.m.)