LOS ANGELES — Jay Leno was the surprise guest at the announcement of his own departure date from NBC when he turned up in disguise on Monday to ask the first few (joking) questions at a news conference here with the co-chairmen of NBC Entertainment, Ben Silverman and Marc Graboff.

Taking a page from Jimmy Kimmel, who showed up as a fake reporter at an ABC news conference last week to inquire about how avidly his network was going to pursue Mr. Leno once he was free from his NBC contact, Mr. Leno put on a bald cap, fake goatee (which only partly disguised his famous chin) and glasses and easily slid among the real reporters to ask the two NBC executives about his own future.

"When is Leno’s last show?" the unnamed reporter asked.

Mr. Graboff then broke the real news that Mr. Leno's last night on "The Tonight Show" would be May 29, 2009, a Friday, with Conan O'Brien taking over the show on the following Monday, June 1.