During John's flashback where Eddie is being introduced at the dinner table, one of John's friends comments on Eddie's 'Geronimo Jackson' T-shirt. 'Geronimo Jackson' was one of the albums found by Hurley when the survivors first gained access to the hatch in Season 2.
When Charlie confronts Locke about where he has been, he says "You were gone for a day...you didn't call. Didn't write." This line is almost word for word what Charlie said to Eko when he returned in Three Minutes (2006), after Eko and Locke find the Pearl Station.
Locke waking up in the jungle, with his eye opening is a recreation of the first shot of the series, when Jack opens his eyes upon arrival on the island.
Charlie speaks of watching shows on "the beeb." This is a reference to the BBC.
Charlie is the third person to tell John "Don't tell me what I can't do". The other two to use John's own line back to him were Eko and Jack.