Experience with SIM-lock free iPhone 3G in "locked" countries

[richard-liu]

I have a Swisscom iPhone 3G. It is SIM-locked for 2 years. Swisscom tells me that I can only use a Swisscom SIM in it during that time. Due to the high costs of data roaming, this means that I might as well forget using it when I'm in Italy for two weeks. An alternative that I'm considering is purchasing in Italy an iPhone 3G without SIM-lock, running it with a prepaid card and an appropriate data plan while I'm in Italy (approx. 2 weeks), then using it with my Swisscom SIM card in Switzerland and selling my present Swisscom iPhone.

I have a few questions:

1. Will the unlocked iPhone work with a Swisscom SIM on the Swisscom network in Switzerland?
2. Will it work anywhere else in Europe with a prepaid card from a local operator, e.g., in France, Austria or Germany?
3. What is the best option for purchasing an iPhone 3G and a prepaid card (incl. appropriate data plan) for a two-week stay in Italy?

Thanks,
Richard