Aegir and uploaded files stored on S3

Has anyone come up with a solid approach for storing uploaded user files (attachments or cck file widget) on Amazon S3? I'm trying out various scenarios for having the files directory hosted on S3, or maybe subdirs of the files dir. I've used the media_mover module though it seems a bit buggy at times. And storage_api seems like a cool approach as well. I guess I could just mount the S3 buckets as a fusefs -- but I'm not sure that would scale very well with many sites.

Due to the nature of platform and many sites sites per platform, it would be great to have a way to have uploaded files and media hosted on a service like S3. It's pretty simple with a few sites, but what about hundreds of sites? Anybody got something similar working? Maybe just one "files" bucket would work best with a fusefs mount and then symlinks for each site?

Thanks for any input.