No, I don't think so. It all depends on what sort of Visa card you have as to whether it's cheaper to use this method so if you want to tell us which one you have? In fact, some are positively more expensive than travellers' cheques.

If you get commission free travellers' cheques, these are 'free' anyway as you pay nothing when you use them in the USA and you can treat them like cash in shops, etc and get change. Just make sure that you get US$ travellers' cheques rather than GB£ ones.