NBC's late-night programming strategy -- handing over the Tonight show to Conan O'Brien and moving Jay Leno to 10 00 p.m. -- may have had the unintended effect of allowing ABC's Nightline to take the lead at 11 30 p.m., according to an analysis of recent ratings by TVNewser.com. The study found that for the entire 2008-2009 season, the ABC news program placed second (to the Tonight show) in total viewers and among adults 25-54, topping CBS among younger viewers for the first time since the 1999-2000 season. Perhaps more significantly, in the quarter from June 29 to Sept. 20, Nightline placed first in total viewers for the first time in 14 years and second among younger viewers.