Internet tethering isn't going to work on the 2G
Just a quick note on the above I was reading on my iphone earlier from the text from 02....
With the internet tethering you need a seperate dataplan bolt on with 02 (not sure about foreign providers) it does not come from your unlimited internet access you already have on the phone.
Prices start at around £14 per month for 3gb (residential users) which is restricted to 3gb on 3G and unlimited over the Cloud/bt openzonei etc - The price drops slightly for corporate users. And the price per mb when you go over is quite steep.
If you are on pay as you go you cannot get/use the tethering service. It is around the same price as a USB dongle so may work out better to get one of those instead.....
The information I am quoting from can be found here:-
Internet Tethering - iPhone