Citibank has a service called "virtual card numbers" which lets you create a specific credit card number that can be limited to a single vendor, a certain credit limit, or a shortish expiration interval. I use it regularly, since I am more concerned about breaches and data theft from a vendor's systems than about my SSL connections being cracked.
Also, don't use the same password everywhere. I have one password I use at websites where I don't really care if somebody impersonates me, and they don't have any stored personal data. Any place else has a unique password for that site only.