this :
http://www.apple.com/fr/pr/20071016orange.html
basically seems to say that if you buy an i-phone in France you will need to do so with a contract with Orange.
My second thought would bebuying an iPhone in Luxembourg, maybe Andorra somewhere with low VAT. But it seems Apple's policy is to only sell iPhones with an exclusive partner that provides communication contracts. I would give Taiwan a try too if I were you.
I read here
http://www.iphonefr.com/viewtopic.ph...amp;action=new
that if you are using an unlocked iphone with the French provider, the provider is able to identify this and it seems they are not too happy about you using an unlocked iphone,They will try to sell you one of their "exclusive" iphones, they of course want to prevent the use of stolen iphones but it seems they can't legally prevent you from using an imported iphone, yet technically they would be able to. same problem may apply elsewhere. Since it is technically possible for yout ISP to Know that you are using an unlocked Iphone, you may expect the law to eventually allow them to block you since the current policy (liberalism) is heading towards more power to the corporations and less freedom to the citizens.
What about looking for a contract wit an ISP that is tailored for a globe trotter like you ? Or maybe waiting for a product that doesn't put so much emphasis on putting handcuffs on the user ?