The black and white stones Jack found in HORS has some religious connotations. The Babylonian Talmud lists the first sign as being that in which "the lot ‘for the Lord’ did not come up in the right hand" (Yoma 39b). What was meant by this? The Holy Scriptures speaks about this ceremony (Leviticus 6:1-34). On the Day of Atonement two identical goats were brought before the High Priest and lots were cast over them (one source says the lots were in the form of a white and black stone—the white stone was "for the Lord" and the black was "for the Scapegoat"). The priest would put his right hand into a receptacle containing the two stones. Without looking, he selected a stone with his right hand and placed it over the right hand goat.

The Babylonian Talmud says that in the previous two hundred years the stone would be sometimes white and sometimes black as most people would have expected (that is, a random selection each year would bring up the black stone as often as the white). But beginning in A.D.30 (the very year in which Jesus prophesied the coming destruction of the Temple, and the very year of his death and resurrection), the right hand of the High Priest selected the black stone every time for 40 straight years! (There is another number 40 reference)

The time of 11:15 was repeated at least three time in HORS, which was the time that Sun was to leave Jin at the airport. A comparison has been made to the passage of Hebrews 11:15:
15If they had been thinking of the country they had left, they would have had opportunity to return. 16Instead, they were longing for a better country—a heavenly one. Therefore God is not ashamed to be called their God, for he has prepared a city for them.

Another interesting comparison is the date 11/15 which is the feast day of Saint Albert the Great, patron saint of scientists and philosophers. This ties three elements of this show together, religion, science and philosophy.
Read more on Saint Albert the Great
Also of note, Saint Albert the Great is also known as Albertus Magnus. He was born under the name Albert de Groot. The term "magnus" is not descriptive; it is the Latin equivalent of his family name, de Groot.

Also see Other Lost Numbers

When Locke asks Charlie if he wants his guitar more than his drugs, Charlie chooses the guitar. Locke suggests that Charlie needs to sacrifice his drugs and the island would give him what he's looking for.

Locke:...."Do you want your Guitar?" (Charlie nods)
Locke: "More than your drug?"
Charlie: "More than you know."
Locke: "What I know is that this island might just give you what you're looking for, but you have to give the island something."
Charlie (giving Locke the drugs): "You really think you can find my guitar?"
Locke: "Look up, Charlie."
Charlie: "You're not going to ask me to pray or something?"
Locke: "I want you to look up." (Charlie looks up and almost cries seeing his guitar)
Excerpt from House of the Rising Sun, written by Javier Grillo-Marxuach