Jack of the Lantern

I was wondering tonight where the idea came from to take a squash, carve holes into it, and put a candle inside.
So here is the Irish tale of Jack, as I learned tonight, from American Catholic dot org. Hmmm.

Jack was the kind of guy who drives me crazy. He was lazy, but smart. Exactly like my teenagers. Smart enough to get out of doing any hard labor. Admirable in many ways, infuriating in others. Anyway, this guy Jack spent a lot of time gambling at the pub, and one day the devil met him there to take his soul. Jack asked him to prove his power by turning himself into a shilling, which he did. Now for some reason, Jack had a scar on his hand in the shape of a cross. When he grabbed the shilling in his hand, the devil was powerless because of the cross touching him. In this pathetic state, the devil was forced into granting Jack one more year of life. Jack's thought was that he'd have plenty of time in that year to repent, but of course being so lazy, at the years end Jack hadn't done jack of repentance.
When the devil came the second time, he was again conned into granting Jack another year of life, this time by a game of dice. The devil threw snake eyes of course, but smart Jack was using a pair of dice he had carved himself and threw a pair of threes that formed the shape of, you guessed it, a cross. A year later, before Jack had a chance to fool the devil again, he found himself at the pearly gates where he was refused. Ditto for Hell, as Satan was still pissed about being tricked. So Jack had to wander around in darkness. Well, he would have, except the devil gave him a hollow pumpkin with a burning coal inside to light his path. Jack of the Lantern he's been called ever since.

Who knew the devil could be so thoughtful?
I still don't see how any of this relates to Halloween though.