Locke is shown inspecting a woman's house. This is Nadia, the woman that Sayid loved and helped to escape in Iraq.
When John Locke goes to deliver the money to his father at the hotel, a plane passes overhead. The tail shows that it is an Oceanic plane.
The number on the safe deposit box where John's father has stashed his money is "1516", which is also two of "the Numbers".
There was an unaired flashback scene cut from this episode. In it Father Chuck asks Locke about his father as he walks down the cemetery with Locke and Helen. This scene appears on the Series 2 DVD.
The serial number on the stationary bike Locke is riding is 084230. A mix up of the "numbers".