The pairing of a very small Linux-based wireless router with do-able battery operation and an open source Linux distribution creates a flexible solution for addressing a lot of undefined problems. A few people have already hacked their way through the details and left instructions for others to follow.
Jason Griffey has created a solution called the LibraryBox based on the TP-Link MR3020 router (less than $40) which allows seamless file sharing of documents on a USB drive for all web-enabled platforms (such as PCs, smart phones, and tablets). Purchase the router and the rest is open source setup available on the web. Working with Linux installs can be daunting but the procedure is outlined in detail here or you could decide to support Griffey’s kickstarter to produce a new version of the LibraryBox and get a configured unit. Cory Doctorow of Boing Boing blog and science fiction fame used LibraryBox at a recent book signing to make free e-book versions of some of his works available to all in attendance.
The LibraryBox is a fork project of the more full-featured PirateBox which allows for uploading files, downloading files, and other communication functions such as chatting. Dr. David Darts is the founder of PirateBox and Matthias Strubel is the lead developer. The PirateBox site includes all the descriptions and instructions needed to get PirateBox up and running on same TP-Link MR3020 router, a Raspberry Pi embedded system, or an Android system. The PirateBox could easily serve as a wireless interactive platform for an extended social event such as a concert or trade show. The PirateBox has already received attention in an article written by Jason Fitzpatrick on the lifehacker.com website.
Both devices are based on the OpenWrt linux distribution for embedded systems that is popular for open source router implementations. The TP-Link router and its siblings are quite the rage in hacker projects, also appearing in this Martin Melchior project documented on hackaday.com.