Apple - Can I develop iPhone apps in Windows?

Nope, you have to use a Mac. All the tools are on the Mac, as is the simulator program you'll need to test in.

Even if you could somehow finagle the whole thing running in Windows you still need a Mac to submit to Apple to get it on the App Store.

Cheapest scenario you're looking $699 for a Mac Mini and $99 for the iOS Developer Program (which you won't need until you want to run the thing on a real phone). You can go cheaper on the hardware if you buy it used but something to keep in mind is that it must be an Intel-based Mac running Leopard (10.5) or higher.

While you can't develop iOS apps on Windows using full-on Xcode, Objective C, and Cocoa Touch, there are some Windows alternatives that will allow you to develop apps. You lose the flexibility and power of the full programming environment and language, but it's no longer impossible.

Here's an article that lists a number of current options. It's not the route I'd go (nor the route I chose), but it's no longer impossible.

Not supported and borderline with piracy but if you dig on Internet you can find how to create a virtual machine with VMware that run OS X. I do not post the link here but using Google is quite easy to find a really well made tutorial about how to proceed with detailed instructions.

I did it before purchasing a MacBook Pro to test how a Web Application I have work on a Mac and so I also used it to install Xcode, if you have a powerful Windows machine the performance are not so bad, but it's useful just for testing and seeing how the different iPhone developer tools works, if you want to develop something business related your only real option is to purchase a Mac.

Regards

Massimo