French mobile phone numbers...

All standard French numbers, mobile or fixed, have 10 digits and start with zero.* The starting two digits reveal the following: 01 Paris and the Ile de France region landlines 02 Northwest France landlines 03 Northeast France landlines 04 Southeast France landlines 05 Southwest France landlines 06 Mobile phones 07 Mobile phones
08 Toll free, local-price, and higher priced national numbers (from airline info to phone sex) When in France, you dial all 10 digits, regardless of where you are, or what kind of phone you're calling from. From the US, you omit the zero, so you dial 011-33-nine digit number. From another European country, you dial 00-33-nine digit number. All of the above also works from a mobile phone (called portable in France). But, you can also use what I call the "plus system" and dial +33-nine digit number, and it will dial correctly, regardless of whether you are in France, the US, or anywhere else in the world. The "plus" in front of the international tells the phone system how to place the call, no matter where you are (thanks, sis, for this trick). So, you can program the number in your phone with the plus and 33 and the number without the initial zero, and you never have to think about it again. BTW, for programming US numbers to do the same trick, you put in +1-area code-number. I always put new numbers in my cell phone this way, so I never have to alter how they are dialed. *Of course, there are special numbers of 3 digits (police, fire and so on) and 4 digits (Air France, SNCF, and probably a few other national companies). NOTE: Edited several times to fix my mistakes and to improve clarity.

Someone asked me in a private message to clarify why I entered US numbers in the plus format, and I'm answering here because it may help other travelers. I have an unlocked quad band phone. When I travel, I change my SIM card from a T-Mobile US one to a local one from the country I'm visiting. I have stored my phone numbers on the phone, not the SIM (a GSM phone allows numbers to be stored in either place). By having the numbers on my phone using the "plus system," this means I can dial them automatically from the phone, wherever I am, without having to modify them in any way. I just press "send," and the call goes through. So: 1. If you are not using your US phone abroad, there's no need to use the plus system to enter numbers on your US phone. 2. I'm not sure what happens if you roam with your US carrier.
3. But if you using a non-US SIM (and therefore have, in effect, a "European" phone), a US number entered as area code and number without the +1 in front won't dial correctly in Europe. Especially since Lindley indicated they needed this information for "pre-trip planning," I wanted to make sure they only had to enter the numbers once, and that they would work from both the US and France.