When Pierre Chang accuses Hurley of being from the future, he asks "Who is the president in 1977?". This is the exact question Hurley feared he would be asked when joining the Dharma Initiative in Namaste (2009).
Sawyer calls one of the submarine crewmen "Nemo". Nemo is the captain of the submarine Nautilus in the novel "20,000 Leagues Under The Sea", by Jules Verne.