Thanks to a tweet by @pypi I discovered collective.backtowork, created by Patrick Gerken.
The package, of which version 0.5.2 was released today, is small but can be very useful. It shows a notification when a Zope instance has started.
It currently only works on Linux systems. If you know how to do something similar for OS X or Windows, please fork the code and add the necessary incantations.
Oh, my Zope instance is ready, so I'm back to work...