That talk about a Britney Spears-Madonna collaboration is just that . . . talk. "It's nowhere near being a reality," Liz Rosenberg, spokesperson for the Material Mom (and recent bride), told the Associated Press yesterday. "It's one of many things Madonna is thinking about in the future." Spears, 19, has said that Madonna, 42, serves as an influence on her. Last night, on the American Music Awards, in fact, Spears seemed to pay homage to Madonna -- by stripping off her pink gown (after being persuaded to do so by LL Cool J) and revealing a tight, midriff-baring halter top and a micro-mini skirt underneath. Madonna, meanwhile, sported a t-shirt bearing the name Britney at a recent concert and even gushed about the younger pop star in the February issue of Elle magazine.