I thought this would be a totally great idea: make a copy of Wikipedia, put it on an external USB2 HD, label/package it nicely and sell it to people. It would be quite useful for people who have slow connections, like developing countries, maybe. And the disk would be reusable when the content became outdated.
Costs: HD, external enclosure, label/packaging, shipping.
Here’s some relevant links:
It seems it is not trivial to just make a dump of the Wikipedia. There is now a function which can export the whole thing as HTML pages, but no documentation yet on how to use it. Alternatively, one could use the database dump, and import it into a local SQL database and run MediaWiki locally on top of the database. The former is certainly easier.