alreadytaken

if it's the alternator, i find it odd that it was fine during the drive home. last time my alternator went out, the car died on the freeway. sure a jump would start it, but it'd keep on dying. if there's nothing charging the battery while you're driving, it should die when the battery falls below 12 volts which really shouldn't take long. maybe it's a bad battery... too week to start the engine, but enough to keep it going..? hey, if it is the battery, that's way cheaper, right?

anyway, if it DOES have to do with the alternator, it may just be a bad belt. that's happened to me, too.

good luck.