In case this acting thing ever falls through for Ben Affleck -- and after ''Gigli'' and ''Paycheck,'' who's to say it won't? -- he can always get a job as a daytime talk show host. He'll show his chat chops on Monday (and get another opportunity to promote the March 26 release of ''Jersey Girl'') when he fills in for vacationing Jersey girl Kelly Ripa on ''Live With Regis and Kelly.'' Apparently, the gig is part of a ''Saturday Night Live'' exchange program; last week, when he hosted ''SNL,'' Ripa made a hilarious surprise appearance in a sketch with him that was a mock ad for the Thailand tourist bureau. On Monday, Affleck will bring with him ''SNL'''s Darrell Hammond, and the two of them will have a ''Reege-off'' to see who does the best Philbin imitation. Who knows, maybe when Regis retires, the show could become ''Live With Ben and Kelly.''