Two popular YA authors, Rachel Cohn and David Levithan, have coauthored a novel for that audience in which each takes the voice of one of a pair of teenagers on their first date. It's called Nick and Norah's Infinite Playlist (shades of the Thin Man!) and was bought by Nancy Hinkel for Knopf Books for Young Readers from Jennifer Rudolph Walsh at William Morris. The book, which will be out next summer, is told in alternate chapters by Nick and Norah, who are pretending to have a date so Nick can avoid a former heartthrob, but who both find the date turning deliciously real. Cohn (Gingerbread) normally publishes with S&S; Levithan (Are We There Yet?) is a Knopf regular.