Slippery Brick reports that it is now possible to run Windows Vista on your iPhone, well after a fashion at any rate. In fact what you get is a Vista emulator called VistaPerfection 2.0 which provides your iPhone with "wallpapers, sliders, sound effects and over 90 Vista-themed icons for everything from the computer to the recycle bin, plus all of the standard iPhone apps. It even gives you a simulated version of Vista’s Sidebar and Start menu."
The iPhone does need to be jailbroken in order to install the thing in the first place, which is one point against it. If you need another one, how about what the heck did you buy an iPhone for in the first place if you wanted something running a Windows OS? Surely the whole point of the God Phone is the clean and crisp and innovative Apple interface? Remove that, and replace it with Vista of all things, and you are left with just another cellphone.