The Associated Press
Saturday, August 5, 2006; 2:43 AM

CHICAGO -- Jay Leno's thumbs are about to get a workout. "The Tonight Show" host is filling in as a guest critic on the movie review show "Ebert & Roeper" while regular co-host Roger Ebert recuperates from cancer surgery.

Leno's appearance with Richard Roeper will air nationally Saturday and Sunday. He will be the first of at least two guest hosts _ director Kevin Smith is slated to host in a show airing Aug. 12-13.

"This promises to be a special experience," Roeper said in a statement. "He's (Leno) been a great friend to our program over the years, and it's a real privilege to have him join me across the aisle."

Ebert, 64, is at a Chicago hospital, where he's in good condition "and improving each day" from surgery last month to repair complications from a previous cancer surgery, the show said in a statement.

This week's episode of "Ebert & Roeper" was taped in Los Angeles to accommodate Leno's schedule.