Original url: http://wiki.daviddarts.com/PirateBox
This is the Pirate Box. It's a Wifi Router with a USB drive which you can access if you happen to have a device that can connect to it via Wifi.
PirateBox utilizes Free, Libre and Open Source software (FLOSS) to create mobile wireless communications and file sharing networks where users can anonymously chat and share images, video, audio, documents, and other digital content.
Simply turn the PirateBox on to transform any space into a temporary communication and wireless file sharing network. When users join the PirateBox wireless network and open a web browser, they are automatically redirected to the PirateBox welcome page. Users can then immediately begin chatting and/or uploading or downloading files.
The PirateBox consists of a wireless router and light-weight Linux server connected to a USB hard drive. The system can run on AC or DC power which allows it to be fully mobile. You can take it to the park, operate it a cafe, in a subway, at work, etc.
This project is released under the Free Art License. The software is totally free and you are completely free to make your own. An elaborate procedure on how to do that can be found right here.
Imagine: A Raspberry Pi computer ($25), with a USB Wifi Dongle (around $20) and a USB memory stick ($5 -> $50). Now you have your own very small Wifi Enabled Memory Stick, which you can set up in your class or office to quickly share documents and other data.