Numbers: The number that Daniel tells Desmond to tell him in the past for the machine frequency is 2.342.
Daniel also tells Desmond to tell him the device must oscillate at 11 hertz; 11 = 23 - 8 - 4.
The betting number for the book Mr. Widmore buys is 2-3-4-2.
Penny's apartment number is 4 23. Penny's apartment number can also be read as to be containing 42.