When in the States you can expect to pay for most of your major expenses by credit or debit card. And hotels and car rental companies will normally ask for a credit card number as security, even if you intend to settle by cash.

American Express, Diners Club, Discover, Mastercard and Visa are among the most widely used.

You'll also need to carry some cash, in one form or another. Here are a few useful tips.

Check with your UK bank before you depart as to whether your cash-dispensing card allows you access to the US networks, thus enabling you to withdraw cash from appropriate holes-in-the-wall.

Otherwise, US dollar travellers' cheques are more advisable than straight currency. American Express, Thomas Cook and Visa travellers' cheques are widely accepted as cash in shops, restaurants and garages and change will be given to you in hard currency.

You should always have a good supply of smaller denomination cheques - $10 and $20 dollars - and ignore 'no checks' signs. These refer mainly to personal cheques. As a rule, travel with US dollar travellers' cheques. Sterling or other currencies are much more difficult to change.

You should also keep a small amount of cash on you to deal with the occasional emergency.