The coming of the Euro is good news for travelers who have been forced to contend with a myriad of currencies and conversion rates up until now. The Euro is now in street circulation, but the pitfalls of gaping spreads, commissions and fees that have made currency exchange the racket that it is today are probably still around for the time being. Making its debut in 12 countries with the beginning of 2002, it is probably only a matter of time before Great Britain and Switzerland get on board, too. Euros can be spent throughout the participating countries, regardless of origin. You will see when you look at the money that each nation has retained a bit of identity, since Euros have a "common" side that is the same for all and then the reverse features engraving by the country in which that particular coin or bill originated.
If you'd like some "walking around money" before you arrive at the continent, a very convenient site to obtain it is: https://www.oanda.com/fxdelivery/ . For an $8 delivery fee plus a bit of a beating on the exchange rate, you can have foreign currency delivered to your door in the U.S. within a couple of days via Federal Express. I don't recommend trading large amounts this way since it's not a swell deal. On the other hand, it can look like a bargain compared to some of the outrageous poundings you will take at those international airport currency exchange booths and even rates that look good on the street signs often feature commissions and fees that turn fair-looking deals into a rip-off by the time you have your money in hand.
The very best way to secure foreign currency on the ground in France is with a Cirrus network bank card. I've yet to have a machine fail to accept my card and the exchange rate is the best you'll receive. Be sure you have a 4-digit PIN. There has been much ado lately about many cards tacking on a 2% fee for this service. While that's not great news, it is small potatoes. Moreover, you will enjoy the same great exchange rate on purchases and credit cards are the way to go. For everyday use, hotels, etc., my choice is American Express. They have local offices on hand and I regard them as the very best when it comes to international travel support.
I've used foreign-demoninated travelers checks and while they offer a measure of safety, they are also a bit of a pain. If you're planning to obtain currency with them, it will not be free of fees, so use them to pay directly for things if you have them. Don't purchase them with the intention of trading for cash unless you are just absolutely paranoid about carrying U.S. cash. Exception: you can generally trade American Express Travelers checks for foreign currency sans fees at an American Express office. You will find these in many large European cities.
A word to the wise: don't spend a lot of time around ATMs in busy areas; don't flash and count wads of cash -- and try to look like you know what you're doing when you make transactions. Leave your expensive jewelry at home. Dress low-key. Be aware of your surroundings. If you are being distracted, jostled, you see a disturbance, you have a lot of kids close by you -- then it's time to WATCH OUT. Thieves often work in teams. I would never encourage anyone to spend an inordinate amount of energy worrying about being robbed, but the fact of the matter is that swindles, pickpocketing and theft are very common in Europe -- more so than here in the States, in my view. It's a hassle you can do without. (There is a reason all those cars have alarms and the shutters aren't decorative -- they REALLY close and lock.)
In the same vein, don't keep valuables in your room; use the safe. Obtain a good money belt to keep your passport, cards and most of your cash safely stashed beneath your clothing (just carry enough in your pocket or purse to cover the immediate expenses you know about). A zippered interior pocket in your jacket is a nice feature. And rather than wear one of those bright fanny packs in front of you where you can keep an eye on your most important items, consider simply wearing a sign that says: "I am a tourist. Please rob me." Okay, sorry for the cynicism, but you get the point. Be safe, be smart and enjoy your trip!