Yes - that would be also be one to consider.
I ended up doing a spike using Net::Amazon::S3, although it needed a minor fix to work with Perl 5.8.8 (pull request issued).
The API isn't the worst, but it all seems like a lot of work to simply access a (secured) file on S3.
I also found AWS::Signature4 which I just could not get to work (all requests rejected for one reason or another). It would be helpful if the AWS signing code was factored out of Net::Amazon::S3.