Add --watch switch that will automatically rerun the tests when files are changed/created/removed.
Hey rejeep, when running inside emacs, I'm thinking of trying something like this to monitor feature files to automatically re-run features: http://stackoverflow.com/questions/3456782/emacs-lisp-how-to-monitor-changes-of-a-file-directory. I'm interested in whether you think that'd be useful? Or were you thinking different ways to implement?
That could work both when running Ecukes from the terminal and from Emacs. You could also use after-save-hook when running from Emacs.
In Emacs 24.4, there a package that could be used for this called filenotify which watches files for changes.