So just boot your Windows machine into OS X, I mean that's what all of the limera1n proponents are telling Mac users to do... oh wait, you can't. Bummer.
Or my other favorite "you don't know ANYONE who owns a Mac?"
All joking aside, I'm glad that redsn0w is finally available cross platform, I wasn't aware that there wasn't a Windows release at the same time as the Mac release of the tool. (The last time I did a jailbreak on a 3G on Windows was back in the QuickPwn/PwngeTool heyday).