I am currently in France. And since my stay in France this time will last for more than two weeks (April/May 2012), I had explored about 3G surfing on mobile phones. I thought I would record my solution here and perhaps someone might find it helpful some day.
Of course, I didn’t invent a solution. Rather, I followed what is said on this webpage -
http://www.feld.com/wp/archives/2011/07/unlimited-mobile-3g-internet-data-in-paris-on-my-android-phone.html (this guy’s writing is quite interesting by the way)
The only things that I have to add are -
1. It didn’t seem possible to get the Orange Mobicarte sim card at the CDG airport. I had a few hours to spare waiting for my train so I walked around the airport train station and a couple of terminals (2A and 2F) and could not find any Orange shop. You can get SFR and other sim cards as well as Mobicarte credits at the Relays, though. Actually when I asked if they had a Mobicarte sim card a shop assistant tried to sell me another brand (“You want a sim card? This is a sim card. Orange? No Orange.”).
2. I got the Mobicarte sim card from the first Orange shop in Aix-en-Provence I came across (there are a lot of these shops in this and other cities). There was one English-speaking shop assistant so communication was relatively smooth (this was very good luck). Because I was a foreigner the shop assistant let me test a dummy sim card to see if my phone could receive the signal. Then he did the registration (he made up some info such as my address) and activated the sim card for me. The startup kit cost 9.9 euros and included the sim card and credit of 5 euros which could be used for phone calls and SMS. I then had to buy and activate the “Internet Max” option – mobile surfing on cell phone for 9 euros per month. So I had to top up some more for the plan (I bought 10 euros and got credit of 12 euros to be used in one month). The shop assistant told me that “Internet Max” covered data of 500 MB per month, not unlimited data. I asked the clerk to handle the purchase of the internet plan for me. He tried but then realised it was not possible until my registration got through to the main system or something, which would take up to 2 days. He did tell me how to do it step by step, which was more or less as described in the webpage above.
3. My attempts to purchase the internet plan kept being denied until about 8 am the next morning (a wait for about 15 hours). After the successful selection of the “Internet Max”, option (it was option 4), I was told by the phone message that the activation of the plan could take up to 48 hours. But by noon that day I found that 9 euros had been deducted from my credit balance so I reckoned that the plan was good to use. That was about 19 hours after the purchase of the sim card, which was far better than the maximum waiting time of 96 hours/4 days. I am now surfing quite happily and it feels great.
4. The confirmation SMS on the subscription of the internet plan did not come until about 1130 the next day.
5. I didn’t know it but changing the sim card has not affected the use of whatsapp messaging at all. There was no need to uninstall/reinstall/reconfigure/reset the app in my phone.
I hope the above info would be useful for someone.