The song played on the piano by Dean is Hey Jude from The Beatles. This is the song his mom used to sing to him as a lullaby.
The name on the card that Sam gives to the bouncer, Lemmy Kilmister, is the name of the lead singer of Motörhead.
The face of young Dean Winchester in the flashback scene was achieved using CGI.
Crowley tells Dean, "I know that you want to keep the party going and have fun, fun, fun til daddy takes the black eyes away." He is paraphrasing The Beach Boys 1964 surf classic, "Fun, Fun, Fun."
The drink Crowley has while at the bar with Dean contains a miniature Devil's pitchfork (as he is Lucifer's replacement as King of Hell).