Gladinet CloudAFS is a file server solution for S3. It can attach S3 as tier 2 storage to file server. On one hand, it publishes network shares to your active directory users. On the other hand, it uses local cache and S3 together to present a file system to the user. It is great for seamless integration of S3 to on-premise IT infrastructure.
It supports Windows 2003/2008, 32-bit/64-bit
You can run it on Windows XP/Vista/7 for personal/home use as well.