Hey, any Entertainment Weekly readers here? There was a good theory printed in the March 3rd edition by Jeff Jensen. You can read it here:

http://www.ew.com/ew/article/commentary/0,6115,1162044_3||1045714|0_0_,00.html

In a nutshell:

The island is/was a research facility studying, amoung other things, parapsychology.

The hatch is a Skinner box. The numbers mean nothing.

The Dharma team studied a subject with super paranormal powers. His name was Aaron. He's haunting the island. He is the black smoke. He needs a new body. Claire's baby is to be that body.

Aaron gave the numbers power.

Not a bad theory eh? This guy is as obsessed with Lost as the rest of us. Check out some other theories he's unearthed here:

http://www.ew.com/ew/article/commentary/0,6115,1170882_3_0_,00.html

Cheers.