iPhone development using windows XP/Vista

For iPhone firmware 1.1.x development

A pre-complied binary for iPhone Toolchain (for firmware 1.1.x) is available.  It is called winchain

http://code.google.com/p/winchain/wiki/HowToUse


For iPhone firmware 2.x development
Please refer to my latest article on the iPhone toolchain SDK2.0 development
on Ubuntu as a virtual machine in Virtual PC 2007 for Windows XP/Vista

http://tungchingkai.blogspot.com/2008/11/personal-installation-guide-for-ubuntu.html

Or if you use VMWare, you can try this
http://iphonesdkdev.blogspot.com/2008/11/upgrade-vmware-image-to-ubuntu-810-for.html

For iOS SDK 4.0 / 5.0
Update for iphone toolchain4 for SDK4.x+
http://github.com/javacom/toolchain4