In addition to perrins recommendation of webchat, I can offer my own module, WWW::Mechanize::Shell, which is a more or less useful generator for WWW::Mechanize scripts. People are using WWW::Mechanize::Shell scripts as standalone scripts too, and simple automated extraction out of tables and batch downloads are easily possible with it too.

What WWW::Mechanize::Shell doesn't do, and never will do, are loops and control structures, as for anything more complicated, you should use WWW::Mechanize, as driven trough Perl instead WWW::Mechanize driven through some ad-hoc shell language.