Say you want to load a Metacello configuration, but your network limits which apps have network access? That's the issue Joachim had to deal with recently:
I needed to get Seaside and some other stuff into a Pharo image on a machine at a place where there is very limited offline access. The network there is configured in a way that not every application can download stuff from the web. Pharo, of course, is not on that list.
Follow the link for details.