BTW, did anyone notice that Jacob gave a gift to each of the people he met in the flashbacks? He gave Kate that New Kids on the Block lunch pail. He gave James a pen or pencil to continue writing his letter. He gave Jack a chocolate bar. He gave Hurley a cab ride and a guitar. He gave Jin and Sun something, but I can't remember -- was it just his blessing? Likewise, with Locke, he gave him hope.
So Jacob seems to play the role of Mr. Destiny in several lives. But I'm not convinced that Jacob is a force for good. Perhaps Jacob's brother (the one who wanted to kill him) is the good one.
