It's certainly possible to develop on a Windows machine, in fact, my first application was exclusively developed on the old Dell Precision I had at the time :)
There are three routes;
- Install OSx86 (aka iATKOS / Kalyway) on a second partition/disk and dual boot.
- Run Mac OS X Server under VMWare (Mac OS X 10.7 (Lion) onwards, read the update below).
- Use Delphi XE4 and the macincloud service. This is a commercial toolset, but the component and lib support is growing.
The first route requires modifying (or using a pre-modified) image of Leopard that can be installed on a regular PC. This is not as hard as you would think, although your success/effort ratio will depend upon how closely the hardware in your PC matches that in Mac hardware - e.g. if you're running a Core 2 Duo on an Intel Motherboard, with an NVidia graphics card you are laughing. If you're running an AMD machine or something without SSE3 it gets a little more involved.
If you purchase (or already own) a version of Leopard then this is a gray area since the Leopard EULA states you may only run it on an "Apple Labeled" machine. As many point out if you stick an Apple sticker on your PC you're probably covered.
The second option is more costly. The EULA for the workstation version of Leopard prevents it from being run under emulation and as a result, there's no support in VMWare for this. Leopard server, however, CAN be run under emulation and can be used for desktop purposes. Leopard server and VMWare are expensive, however.
If you're interested in option 1) I would suggest starting at Insanelymac and reading the OSx86 sections.
I do think you should consider whether the time you will invest is going to be worth the money you will save though. It was for me because I enjoy tinkering with this type of stuff and I started during the early iPhone betas, months before their App Store became available.
Alternatively, you could pick up a low-spec Mac Mini from eBay. You don't need much horsepower to run the SDK and you can always sell it on later if you decide to stop development or buy a better Mac.
Update: You cannot create a Mac OS X Client virtual machine for OS X 10.6 and earlier. Apple does not allow these Client OSes to be virtualized. With Mac OS X 10.7 (Lion) onwards, Apple has changed its licensing agreement in regards to virtualization. Source: VMWare KnowledgeBase
If using Xcode 4.2 or higher, try the following:
Click your Project name (in the left column), followed by the Target:
Click the 'Build Settings' tab (in the right column):
Click the 'Release' or 'Distribution' row under 'Architectures', and choose 'Other...':
Double click the highlighted row named '$(ARCHS_STANDARD_32_BIT)' in the popover that appears, and replace it by typing 'armv6'. Then add a new row with the plus button in the bottom left of the popover, and type 'armv7', then click Done:
Update: you should add armv7s to target the iPhone 5 as well. (And drop armv6 if building with Xcode 4.5 or higher, which no longer supports armv6.)
That's it. You should now be able to build/archive without generating errors.
If it still doesn't work, see this answer from justinxreese, which suggests adding entries for armv6 and armv7 under "Required Device Capabilities" in your info.plist file.
Best Answer
Despite iOS being a resolution dependent OS, stage resolution doesn't matter. It will look the same if the stage resolution was 240x160 or 1920x1280. The device will render the game to it's native resolution. This is why you need to set the resolution in the publish settings: so that flash knows to add support for those resolutions for iOS. Setting the stage to 960x640 should be fine for the iPhone. When it publishes for iPad on the other hand, it will be built to it's native screen resolution, but because the iPhone and iPad have different aspect ratios, the iPad will have more space on the side. Since the game will be in landscape mode, it should be ok to simply put to thick black rectangles on the top and bottom of the stage.
As for the new iPad resolution, Flash isn't powerful enough to support that resolution, it will export to the standard iPad resolution of 1024x768 even if the resolution is set to high in the publish settings.
So pick the stage resolution based off of what device you favor, if you want the app to look best on the iPad's format, go for 1024x768, but the iPhone will have extra space on the sides in landscape mode. The same goes for the iPhone resolution I explained earlier. Although, if you'd like to fully support both, you can try many methods used to position GUI elements on the vast sea of Android Screens based off the Capabilities.screenResolutionX and Capabilities.ScreenResolutionY methods in flash.