We've got E-book readers showing up now, Kindle, OLPC-XO (G1G1), and the like. We've also got fairly widespread laptops, sub-notebooks, iPhones and N800s. Most of them are going to have local-network (wifi) connectivity free. People are manually downloading media on these machines to consume it on the subway/bus as they commute to work. At the same time, lacking media to read, people are reading free-daily newspapers (and tearing up the forests to do it) to fill the time.

So why not set up your free-daily newspaper distribution box to work as a wifi node with an Avahi connection that advertises an RSS feed of your newspaper? It doesn't need broader network connectivity, just the ability to have anyone connect automatically and download the files.

Your clients would then be programmed to hop onto public wifi hotspots and look for signed broadcasts of a given set of publishers (given set of feeds). They would download the file as you pass the box out front of the subway station and you can read it on the subway. Save the paper and let the people read the paper.

For bonus points, have the distribution box automatically download signed copies of the paper from the truck (without driver interaction).

For killer-application points, have any two clients able to advertise/discover and share the signed content, so that if you didn't catch the content as you walked into the subway you can pick it up from anyone else on the train/bus.

You'd need a mechanism for browsing available feeds (including their expected download time). A standard way of identifying and signing the feeds (GPG or what have you), storage for the set of feed signatures and preferences, and a reasonable way of letting the user unsubscribe.

Advertisers would likely also like some way of tracking downloads/usage, but that's going to be tricky in the offline world, for now I'd punt on it. Observe usage patterns on the subway (send in someone with an instrumented machine that tells you how many people are offering/requesting a given resource and extrapolate from that) for the first pass operations.