Hey,
I've got a couple of applications in the App Store at the moment which I've had ready after the release of iOS4. If I try and download one of these in the App store on a 3.x device, it will tell me I need to upgrade. Is there a way to make my application not do this, as I don't think I am using any API calls specific to iOS4.
I originally thought that this could not be done but I just now installed 'Plants vs Zombies' and 'Angry Birds' on my iPod Touch (running 3.1.3) so it must be possible as I'm sure these have released updates recently, and being in the top5 games, I would have thought they were developed using the iOS4 SDK. I am hoping it is just one value somewhere but if anyone could let me know how to do it that would be awesome :).