Widget Creator
Andy Herbert recently announced a Widget Creator bundle (direct link to the bundle). This allows you to create a Dashboard Widget from your current document, be it a Ruby, Python, Perl, shell, or whatever script.
The created widget will then run the script when clicked and you can optionally drag files or URLs to this widget (e.g. from Finder or your web browser), and the script will receive the dropped items as arguments.
There is a screencast showing the Widget Creator bundle in action.
So if you don’t like to write contextual menu plug-ins or compile AppleScripts into applications, in order to get custom (drop) actions in Finder, this bundle provides you with an easy alternative!