If you do have an AmEx, that's definitely grounds for thought, although they will be able to tell that you don't have new debt, you just parked it somewhere else for a while.
I couldn't tell for sure if you have one, but if you do, which card, how long, and what's your usage and payment pattern?
I see the logic in the BT, but I would only move over enough to keep it at 90% or less on each, including the $75 fees, and pay them down frantically fast, at least until I got them at 49% or less. You'd have to still pay a bit of interest on whatever you didn't transfer, but that little 10% cushion could save you.
And as the others said, mark it off on a calendar to have it paid off by the end of the promo period. With some CC's, if you don't pay in full before the 0% is up, they will charge you interest on the original amount, as if you had never paid the rest off at all! Read the agreements carefully, and even then, realize that there might be something hidden in there.
And finally, bury the cards deep in the sock drawer so that you don't accidentally use one for a charge.
Financial benefits beat scoring benefits in cases like this, but you do want to watch out for collateral damage with other companies, as you are doing. Good luck!
* Credit is a wonderful servant, but a terrible master. * Who's the boss --you or your credit?
FICO's: EQ 781 - TU 793 - EX 779 (from PSECU) - Done credit hunting; having fun with credit gardening. - EQ 590 on 5/14/2007