Frommer's lists exact prices in local currency. However, rates fluctuate, so before departing consult a currency exchange website such as www.oanda.com/currency/converter to check up-to-the-minute rates. For help with currency conversions, tip calculations, and more, download Frommer's convenient Travel Tools app for your mobile device. Go to www.frommers.com/go/mobile and click on the Travel Tools icon.

The cost of living is not cheap in San Diego, but it's still a moderately priced destination compared with New York, London, or Tokyo. It's always advisable to bring money in a variety of forms on a vacation: a mix of cash, credit cards, and traveler's checks or prepaid debit card. You should also exchange enough petty cash to cover airport incidentals, tipping, and transportation to your hotel before you leave home, or withdraw money upon arrival at an airport ATM.

Nationwide, the easiest and best way to get cash away from home is from an ATM (automated teller machine), sometimes referred to as a "cash machine," or "cashpoint." The Cirrus (tel. 800/424-7787; www.mastercard.com) and PLUS (tel. 800/843-7587; www.visa.com) networks span the country; you can find them even in remote regions. Go to your bank card's website to find ATM locations at your destination. Be sure you know your daily withdrawal limit before you depart. Note: Many banks impose a fee every time you use a card at another bank's ATM, and that fee is often higher for international transactions (up to $5 or more) than for domestic ones (where they're rarely more than $2). In addition, the bank from which you withdraw cash may charge its own fee. To compare banks' ATM fees within the U.S., use www.bankrate.com. Visitors from outside the U.S. should also find out whether their bank assesses a 1% to 3% fee on charges incurred abroad.

Credit cards are the most widely used form of payment in the United States: Visa, MasterCard, American Express, Diners Club, and Discover. They also provide a convenient record of all your expenses, and offer relatively good exchange rates. You can withdraw cash advances from your credit cards at banks or ATMs, but high fees make credit card cash advances a pricey way to get cash. It's highly recommended you travel with at least one major credit card. You must have a credit card to rent a car, and hotels and airlines usually require a credit card imprint as a deposit against expenses.

Beware of hidden credit-card fees while traveling. Check with your credit or debit card issuer to see what fees, if any, will be charged for overseas transactions. Recent reform legislation in the U.S., for example, has curbed some exploitative lending practices. But many banks have responded by increasing fees in other areas, including fees for customers who use credit and debit cards while out of the country -- even if those charges were made in U.S. dollars. Fees can amount to 3% or more of the purchase price. Check with your bank before departing to avoid any surprise charges on your statement.

For help with currency conversions, tip calculations, and more, download Frommer's convenient Travel Tools app for your mobile device. Go to www.frommers.com/go/mobile and click on the Travel Tools icon.

Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.