Paw HTTP Client
When developing Web apps you spend a lot of time in the browser, and before long you have a crap-ton of open tabs which slows the system down and is a total pain to navigate around in.
Testing
Testing with "latest"
A few months ago I gave a small talk at the Nordic Perl Workshop 2013, about a clever way of combining cpanm and local::lib to test your CPAN modules with the latest version of its dependencies.