The production worked almost entirely with natural light and without makeup. Lighting was only used for some night scenes.
David (Colin Farrell), Robert (John C. Reilly) and John (Ben Wishaw) are the only named characters in the movie.
The movie was mainly filmed in and around the Parknasilla Hotel in Sneem, County Kerry in Ireland.
The song that David and the short-sighted woman synchronize their CD players with, and dance to in the woods, is "Where The Wild Roses Grow" by Nick Cave & The Bad Seeds featuring Kylie Minogue.