They're everywhere. I've heard (mousesavers.com) that the *yellow* ones - any company - have an agreement with Disney and are fine to use. Other cabs do not have the same agreement and there have been horror stories about being driven 10 minutes and then told you owed the driver some ridiculous amount of money. There should be plenty of yellow cabs around, though. I know that one of the 'greeters' at Pop called one over for us last year and I'm sure that anyone involved in guest services could do the same.....