Q: I travelled to US And When I came back in France, I can't connecte to french  iTune store. Could you reconnecte me to french iTune store? Thank you

App Store Frequently Asked Questions (FAQ) - http://support.apple.com/kb/HT2001 when using iTunes --> "To change countries, scroll to the end of the iTunes Store home page and click the flag indicating the current country. To choose a different country, click the appropriate flag."

iOS: Changing the signed-in iTunes Store account - http://support.apple.com/kb/HT1311  - Change your iTunes Store country: "Sign in to the account for the iTunes Store region you'd like to use. Tap Settings > iTunes & App Stores > Apple ID: > View Apple ID > Country/Region."http://support.apple.com/kb/HT1311