Popular Mechanics has an article that says it just might be possible to move the island using the electromagnetic fields of the island:
So just how can Locke move the island–-and where will he move it, for that matter? Michio Kaku, author of “Physics of the Impossible,” told us he thinks that Damon Lindelof and Carlton Cuse are using the island’s unique properties —namely its electromagnet and the Casimir Effect hinted at in the Orchid Station orientation video—to open a transversible wormhole to different points in time and space. (Über-baddie Keamy seemed to verify that when he pulled the Orchid-Station-emblazed “secondary protocol” from the ship’s safe. He said the document would tell him “where Linus is going. If Linus knows we’re going to torch the island, there’s only one place he could go.”)
Read the rest at Popular Mechanics.