From Entertainment Weekly's recap of the ep:
And then there's that manuscript, the one Hurley was reading before Sayid came along to play radio...The book is Bad Twin, by Gary Troup, a mystery writer who boarded flight 815 and is now presumed dead. From Amazon (where the ''real'' book will soon be sold, in a gloriously meta tie-in):
Paul Artisan, P.I. is a new version of an old breed — a righter of wrongs, someone driven to get to the bottom of things. Too bad his usual cases are of the boring malpractice and fraud variety. Until now. His new gig turns on the disappearance of one of a pair of twins, adult scions of a rich but tragedy-prone family. The missing twin — a charismatic poster-boy for irresponsibility — has spent his life daring people to hate him, punishing himself endlessly for his screw-ups and misdeeds. The other twin — Artisan's client — is dutiful and resentful in equal measure....Troup's long-awaited Bad Twin is a suspenseful novel that touches on many powerful themes, including the consequence of vengeance, the power of redemption, and where to turn when all seems lost.
The dueling dualities continue. Locke and Eko? Ana-Lucia and Jack? Sawyer and Kate? All light-dark pairings, all ''twins,'' in a sense.
Oh, and speaking of Sayid's new radio: Who's biting? The Lost writers must be impatient: They're dropping hints right from the mouth of Hurley. ''The signals...could be coming from anywhere,'' said Sayid, after they tuned in what sounded like an American oldies station. ''Or any time,'' said Hurley. Pillsbury, my man: You're pre-geeking us! Don't do that! You'll put us out of a job! (By the way, it's been noted: The station's initial call letter was a W, which would make it in the eastern half of the U.S. The full title: WXO, which are letters 23, 24, and 15 of the alphabet. Make of it what you will.)