Then you're out of luck, sorry dude.
The iPhone is based on Cocoa and the OSX 10.5 software, not windows, so you're gonna have to at least buy a Mac Mini if you wanna code for the iPhone.
And don't even start complaining (aka "well why can't I on an XP?"). Just don't. The iPhone was built on 10.5, so 10.5 is the ONLY way to write code and apps for it.
And objective-c isn't simple. It's gonna take some time to learn how to code.