I've removed the dependency on the Perl package XML::Simple, and replaced it with calls to XML::LibXML, which will have already been loaded because Net::Amazon::S3 depends on it.
I really dislike doing what should be a minor update via CPAN, and having a cascading set of added dependencies cause CPAN to pull in the whole world. So I shall swim upstream, and remove unneeded dependencies.
The tarball can be had at http://fallenpegasus.com/code/s3-tools
The Mercurial repo is at http://hg.fallenpegasus.com/s3-tools