There are four french mobile phone providers:

1. Orange: www.orange.fr
2. SFR: www.sfr.fr
3. Bouygues Telecom: www.bouyguestelecom.fr
4. Free: http://mobile.free.fr

Thanks to a European Union regulation, roaming charges are now forbidden within the EU for short stays. This means that you can use your phone without any extra cost in another country of the EU. Calls to a foreign country (including EU countries) are however still charged extra.