Jimmy Fallon testing 'Late Night' waters online

Web spots will run for months before he takes over as host

Jimmy Fallon's debut as the new host of "Late Night" will come online, not on television.

Fallon, who will take over the NBC show when its current host, Conan O'Brien, replaces Jay Leno on "Tonight" next year, will hone his approach in brief Internet shows, "Late Night" producer Lorne Michaels said Sunday.

Fallon, a former cast member of Michaels' "Saturday Night Live," will appear online for several months before beginning his stint on the broadcast show.

Michaels knows that seasoning can be valuable: The producer picked O'Brien out of obscurity to fill Letterman's old slot at NBC, then stuck with him despite savage early reviews.

Michaels spoke to reporters attending the Television Critics Assn.'s summer press tour, where NBC on Monday could announce the timing for its late-night musical chairs.

Despite its primetime woes, NBC has managed to maintain its late-night ratings dominance, though O'Brien has been challenged lately by Craig Ferguson on CBS. Now NBC is attempting a tricky transition based on a promise made nearly four years ago that O'Brien would succeed Leno.

Leno continues to be the king of late-night and the network is trying to keep him at NBC Universal with some job other than "Tonight" host.

However, Leno said recently that he's done with NBC next year, and networks and syndicators are poised to woo him when he's free to open contract talks.