The game 'Mouse Trap' is seen in the game room. Mouse Trap was of extreme symbolic importance in Deus Ex Machina (2005), where John's description of the game to a young lad turned out to be a dissertation on the fraud that was about to befall him at the hands of his father, Anthony Cooper.
When Juliet punches in the code to activate the monster fence, the code utilizes part of LOST's mystical number sequence: 4, 8, 15, 16, 23, and 42. You can see her enter 16 and 23.
The societal allegory book 'Watership Down' makes at least its second appearance on LOST in Sawyer's hands.
In the flashback, the woman who assists Kate in Iowa is Sawyer's ex-girlfriend that he conned, Cassidy Phillips (Kim Dickens).