I like Wx::Perl (link above) and have found it relatively easy to build a file list panel which you drag files or folders onto and it remembers and lists all the contents to do something to them. It may take a little while to get used to it but is very powerful.

Also have used Win32::GUI a couple years ago, it was easy for really simple things but wasn't what I was looking for. The wxperl mailing list also has good people responding to questions, I'd recommend it.