Spacey Sings

TUBE TALK Boosted by returning Thursday favorites ''Friends'' and ''ER,'' NBC won the Nielsen ratings week that ended Sunday. The season premiere of ''Friends,'' which confirmed Rachel's pregnancy, was the week's top show, drawing 31.7 million viewers, while the ''ER'' premiere was the second most-watched show, with 28.2 million viewers. For the week, NBC averaged 13.5 million viewers, followed by CBS (12.6 million), and ABC (11.8 million). Fox, which is saving most of its new lineup until after baseball season, drew 6.9 million viewers. UPN, blasted into warp drive by the premiere of ''Star Trek: Enterprise,'' averaged 5.7 million viewers, its best weekly showing in four years. The WB, like Fox, has yet to debut its new shows, and it drew 3 million viewers.

It seems unfair to guess which new series will be hits based on just one week of ratings, but then, that's how ruthlessly the impatient networks will judge them, too. Strong debuts include ABC's ''Alias,'' NBC's ''Crossing Jordan,'' CBS' ''The Guardian,'' and UPN's ''Enterprise'' Slower out of the gate were CBS' ''The Agency,'' ''ABC's ''Philly'' and ''Thieves,'' Fox's ''Undeclared,'' and NBC's Sunday series ''Law & Order: Criminal Intent'' and ''UC: Undercover.'' Shows already being circled by buzzards are NBC's ''Emeril,'' Fox's ''Pasadena,'' and CBS' ''The Ellen Show,'' ''Danny,'' and ''Citizen Baines.'' Then there's NBC's ''Inside Schwartz,'' which, sandwiched between ''Friends'' and ''Will & Grace,'' was the most-watched new series, but it still lost a third of ''Friends'' viewers. Welcome to the weird world of TV ratings, where a top 5 show with 22.6 million viewers may be considered a flop....

As EW.com reported yesterday, the networks are rushing to recruit big-screen actors for small-screen series. They're also trying to adapt some big-screeen movies. ABC has a deal with MGM for a sitcom version of ''Legally Blonde'' for next year, even though MGM is also planning a sequel for the multiplexes, one which, unlike the TV version, will star Reese Witherspoon. At NBC, writer/director Jake Kasdan is planning to adapt his 1998 detective movie ''Zero Effect'' into a one-hour drama series. The film wasn't a huge hit in theaters, though it gained a cult of fans on video and cable. The series would be a prequel of sorts, tracing the early adventures of reclusive sleuth Daryl Zero (played in the film by Bill Pullman) and exasperated partner Steve Arlo (played originally by Ben Stiller).

BIRTH DAY She starred in ''Foxes,'' so it's no wonder she named her child Kit. Jodie Foster gave birth Saturday to a son, weighing 6 pounds, 3 ounces. Kit is the 38-year-old actress's second child; son Charles is 3.