Credit cards are now widely accepted. Visa often called Carte Bleue in France is almost universally recognized, followed by MasterCard (also known as EuroCard). American Express ranks a bit lower. It's worth bearing in mind that some smaller places either don't accept cards, or only for sums above a certain threshold. Be aware, also, that French cards have a smart chip, and machines may reject cards with a magnetic strip even if they are valid.
You can also use credit cards for cash advances at banks and in ATMs, which give you the choice of instructions in various European languages. Remember that all cash advances are treated as loans, with interest accruing daily from the date of withdrawal; your bank may levy a transaction fee on top of this. However, you may be able to make withdrawals from ATMs using your debit card, which is not liable to interest payments, and the flat transaction fee is usually quite small your bank will able to advise. Make sure you have a personal identification number (PIN) that's designed to work overseas; in France you'll need a four-digit PIN.
A compromise between travellers' cheques and regular credit/debit cards is Visa TravelMoney, a disposable pre-paid debit card with a PIN which works in all ATMs that take Visa cards. You load up your account with funds before leaving home, and when they run out, simply throw the card away. You can buy up to nine cards to access the same funds useful for couples or families travelling together and it's a good idea to buy at least one extra as a back-up in case of loss or theft. If you need assistance, call the 24-hour toll-free number tel 08.00.90.11.79. The card is available in most countries from branches of Thomas Cook and Citicorp. For more information, check the Visa TravelMoney page at usa.visa.com/personal/cards/visa_travel_money.html.
To cancel lost or stolen cards, call the following 24-hour numbers: American Express tel 01.47.77.72.00; Diners' Club tel 08.10.31.41.59; MasterCard tel 08.00.90.13.87; Visa tel 08.00.90.11.79.