Travel Technology - 3G phone on non 3G network

This may sound like a seriously stupid question but I may have an iPhone 3G (without the S) on my way - unlocked and all.

I'm in Sweden and my provider is only 3G (monthly and paygo) Now, will it work if I go to, i.e. Germany, stick another sim from another provider? Even if that is not a 3G sim?

How do you guys with unlocked 3G iphones work that? Do you care if the sim is 3G or not?

And pardon me if my question is confusing. I'm confused myself.

Yes. It should work. You just will not get 3G voice/data. You will be using GSM. It's just like using the Iphone with tmobile in the US. Just like a lot of people are doing. It's just that data will be EDGE and voice will be regular GSM No problems doing that at all. I hope answered what you were asking.

That answered my question, thank you very much.

Now fingers crossed I snap it up. I'm sick of the old SonyEricsson.