Tom's primal underwater scream was an idea actor Chris Zylka had on set. It became one of the defining moments in HBO's advertising for the series.
The Guilty Remnant, and their practices and philosophies, come directly from the book, including the white clothing, the smoking, the vow of silence (and scribbling their communications in notebooks), always traveling in same-sex pairs, and acting as Watchers. The smoking is described by one character as being like a sacrament; the G.R. believes they will not be around long enough to get cancer, as the Bible says there are only seven years of Tribulation after the Rapture.
Famous departed: Condoleezza Rice, Salman Rushdie, Shaquille O'Neal, Jennifer Lopez, Anthony Bourdain, Gary Busey, Bonnie Raitt, and Pope Benedict XVI.
Damon Lindelof came up with Patti's line, "You and I won't speak again," on set as they were shooting the scene.
The options on the Get a Room app are: Screw, Hug, Burn, Hickey, Suck, Choke, Bite, The Tip, Titty, Fuck, Kiss, Slap.