Thanks. I wasn't aware that this would still be considered a new line of credit. I'll likely be keeping one or two non-fee cards around anyway (Amex Blue Everyday and the two Fidelity Rewards cards I have), so it sounds like there is no point at all to keeping this US Air "free" card open whatsoever.

That does pose a side-question then. Would I be able to keep this card open just for the heck of it and then still apply for a new US Air "fee" card down the road and take advantage of the bonus sign-up again? Or only if i cancel the free one first?