Here are the links from this post reposted here for those that want a single post with all of them (also removed duplicates and made sure all these sites still exist):
Being essentially new to Mac products, is it even possible to use Iphoto w/ a Windows based OS? If it is not possible, how can I import photo's to the Iphone.
You should be able to do it with any image editing software (yes, even Paint for Windows). Just make the image have the size you need and then sync the resulting image to your iphone.