An open source convention badge. The idea behind this is to have a very low cost, low power electronic badge. These could be built just for fun, or if you're throwing a conference, feel free to use the PCB as the badge, maybe build some, maybe let the folks at the conference build them.
Electronic badges have gotten pretty hip, but they seem to suffer from two primary problems: They are very expensive, and they need a lot of batteries.
The goal of the Open Badge Project was to build a badge that costs $5 or less and can run for a day or more on one 2032 battery.
The badge as it stands right now will only cost $5 if you build A LOT (1000 or more). The cost is closer to $6 or $7 for smaller batches at the moment, but that's still pretty reasonable.
The badge itself runs on a microprocessor called an ATTINY85. It has 8K of program space, 512 bytes (yes, bytes) of memory. That microprocessor then drives 3 shift registers. One for the button input, and two for the display output. Shift registers shouldn't be used to drive LEDs, but it works, and doing it this way keeps the cost down.
Honestly, this site started as a joke. A weekend script tossed together to consolidate PCB orders from the Dangerous Prototypes team. It sat quietly and unnoticed until Hack a Day told the world. Turns out people like cheap, no-nonsence PCBs at near-China local prices and no-markup shipping. The original script, not even worthy of the word "store", ran for three years and handled tens of thousands of orders.
Over that time we've hacked together new interfaces to cool services in China, and cobbled them together into this store. It is highly experimental and many things are still a bit rough around the edges! Welcome, the PCBs are cheap and the 3D printing is amazing!
They even have Hacker Shops, which is where folks sell their projects (sometimes just boards, sometimes kits, sometimes assembled things).
Fritzing is an open-source graphical application for converting a project prototyped with an Arduino into a PCB schematic for manufacture. Designed for people already familiar with Processing to do what they need to do easily. Cross platform: runs on Windows, OSX, and Linux.
RepRap is an open-source (hardware, software, and documentation) desktop fabrication system which lets you construct arbitrary objects (or parts for assembling more complex systems). It's unique in that you can construct one yourself for about $400us, and it is fully capable of making duplicates of itself.
An open source DIY robotics/rapid prototyping kit much like an Erector set. Lots of standardized pre-milled bars, rods, connectors, and components. Build your own plotter, CNC machine, RepRap, scanner table, or what have you. Capable of three axes of linear motion. Comes with all the electronics you need, including an Arduino, stepper motors, and a motor driver board.