Our internet is with Free, and I like them very much. They're very geeky, they have lots of gadgetty things (like a remote control for the TV box that works by wifi) and the bill is reasonable. They also support Open-Source software very actively.
The boss of Free announced some time ago that Free wanted to move into the mobile phone market and "Halve the mobile phone bill for French families". It's true that mobile phone bills are REALLY EXPENSIVE in France compared to the UK.
Anyway the legal process is long, but eventually they launched their offers yesterday - 16€ / month for unlimited calls, unlimited SMS etc and 3GB of 3G data - speed reduced after that, and Skype use and mobile tethering all allowed. Also unlimited calls include those to UK landlines.
Well there was a feeding frenzy. It was fun to see friends trying to connect and reporting their frustration.
Didn't work for me either. Firstly I couldn't get into the website. Then I couldn't get it to accept my password. Then it wouldn't accept my bank details. I gave up.
Tried this morning. All fine. Signed up. Yipppeeeee ! Once everyone else is out of contract we can all move across and cut our mobile bill enormously.