Basically, growl notifications (or other callbacks) when tests break or pass. Does anything like this exist?
If not, it should be pretty easy to wri
Guard is an excellent tool that monitors for file changes and triggers tasks automatically. It's written in Ruby, but it can be used as a standalone tool for any task like this. There's a guard-nosetests plugin to run Python tests via nose.
Guard supports cross-platform notifications (Linux, OSX, Windows), including Growl, as well as many other great features. One of my can't-live-without dev tools.