So I've been looking for a way to get index pages on Amazon S3. Turns out Amazon doesn't provide them, and nobody else really does either. Well, we can fix that!
I just put together http://s3index.p-static.net, which generates index pages for any S3 bucket. If your bucket is publicly listable (go to bucket permissions, and enable "List" permission for "Everybody"), then it should work. The URL format is http://s3index.p-static.net/BUCKETNAME.
Bonus: it's stylable! The script automatically includes a CSS file named "s3index.css" in the bucket, and all the elements have classes declared.
Source code coming later, it's still extremely messy right now. >_>