Best way to create password-protected photo galleries on S3?

I'd like to host my photo galleries on Amazon S3. Some would be public, some password-protected. Wha开发者_StackOverflowt is the best way to achieve this? As far as I know S3 doesn't supports .htaccess files.

Thanks, Istvan

It is "possible" to manage user permissions in S3 natively, but it's not really practical or scalable.

A much more practical solution (in my opinion) is to manage authentication and permissions in some other web application and then have that application provide temporary (expiring) links to the files in S3.