I've refactored iplayer-dl in order to make it easier to extend and wrap. As a direct result, it's no longer just one script. As a result, you'll need to install the libraries and command-line script in order to use it.
The good news is that this is as easy as typing:
ruby setup.rb config sudo ruby setup.rb install
Windows users should omit 'sudo' in the second line.
You can then run the downloader just by typing: