Hi,
is there a way how to make sure that the build will be compatible only with the iphone 3g and 3gs (and also ipod equivalents) and not with the iphone 4?
I set the flag architectures in xcode project settings to armv6 and checked the build active architecture only.
Iphone deployment target is set to os 3.0.
Is that OK?
That won’t prevent it from running on the iPhone 4, nor can I imagine a reason why you’d do that. Even if it was possible I doubt Apple would approve it.
–Eric
Exactly, disallowing it from running on iphone4 / itouch4 (or just retina) means straight reject
You can cut off pre 3GS devices, pre iOS4 devices etc. But you can in no way restrict the current generation from running it or apple will prevent you from even getting your app onto the store.
Also there is no reason to restrict it actually, as the iPhone 4 is all what previous had + higher resolution.
If it performs badly you can always force it to upscale the rendering through some tricks on the xcode project
OK, thanks a lot for the answers 
not sure why you would want to do that, but i am using unity iphone 1.7 and the builds look great on my iphone 4.
I can also confirm what etomp said. I was concerned about how my app (at 480x320) would look on iPhone 4, so went and bought an iPod with Retina display. I can tell you it looks and behaves perfectly with no effort on my part (just ensure in player settings you set Target Resolution as Standard.