Yeah but data on prepaid SIMs is not cheap. I loaded one web page on an Italian SIM and it cost more than 1 Euro of my credit. I don't even know if it was using 3G data either.

Looking at most of these international plans for the iPhone 3G, there are few that offer unlimited data. So while 3G may be in all these other countries, looks like it's too costly for heavy use, unless you subscribe to special plans.

And from what I recall, the Hong Kong plans for the iPhone 3G were some of the most competitive around.

But the non-contract price is a bit too much. You can probably do some light international roaming (but not of data) before you spend as much as you would for these non-contract iPhones.