Sn0wbreeze V1.6 has been Released minutes ago to Jailbreak iPhone 3GS, iPhone 3G, iPod 2G on iOS 4 for Windows users, Now I tried it and it's working on Windows, So if you didn't jailbreak yet (or don't know how) here's the step by step guide posted below..
http://www.mediafire.com/?nj03emmtiyo