Im looking forward to have an interrail in France. Im wondering what are the best free internet wifi spots I can find in several cities in France.
Beside the hostels...Starbucks? What about the small villages?
The sure-fire way of getting coverage almost everywhere is a 3G connection.
A lot of towns have installed wifi hotspots that are free and open to everyone. They are generally located in parks or near the town hall, sometimes near tourist information booths. The bigger the town, the more of a chance you have, but on the other hand some rural villages have a public hotspot intended for inhabitants who are less likely to be able to have a broadband connection at home (because they can't afford it or because they're too far from the phone exchange for DSL). I'm not aware of any site that lists them all; you can generally find out by searching for
Wifi for customers in hostels and hotels is fairly common in Europe (sometimes only in the reception area). More so in places that accommodate business travelers and backpackers than those that mostly cater to families, but in this era of tablets even families expect to remain connected while on holiday.
SFR (one of the big mobile phone operators in France) has a fairly extensive wifi network, including many major train stations. Unfortunately, it's reserved to SFR customers, and I don't think there's a decent offer that enables this wifi access if you don't live in France. There are plans to open this network to everyone some time in 2012, but I don't think this is up yet.
If you have a broadband connection at home, consider joining Fon. The principle is that you let others use your wifi connection, and others let you use theirs. Some ISPs let you participate in Fon by ticking a box in your router configuration, including SFR in France. If your ISP isn't a partner, you'll need to buy a Fon-specific wifi router; it's up to you to decide whether the price is worth it (there isn't a high markup on these router). Fon coverage is spotty in France, so this isn't a sure-fire solution. Every medium-to-large town has a Fon somewhere, but it might only be out in the suburbs. So this is more of a complement than a complete solution.
Not to answer your question, really, I think you should consider getting a prepaid data plan (in France), assuming the device you're carrying is a smartphone of sorts, or a tablet with 3G capability. If you're carrying a computer, get a 3G dongle with a data plan.