Kiaora!

I've been looking to buy a smartphone for a while now. I looked around HTC Nokia, but iPhone always came out on top.

With the release of the iPhone 3g it seems to me the only changes from the previous EDGE version are purely superficial, eg. GPS (that no man should need), and a plastic back (the metal back looks way cooler!). I don't use mobile data and will primarily use WiFi for data, so 3G is useless to me. So i'm looking to get a 1st Gen iPhone from tosh computers.  Does this seem the logical conclusion?

If I buy an iPhone and unlock it which features will work here?
Obviously Visual voicemail won't work, but a hack may become available when Vodafone releases the 3G. But does call merging etc. work?

Can I expect location services to work as well or will that incur charges?