Here is a collection of all the Open Source Hardware projects I've been able to track down In general, a project must have some electronic component and have at least firmware open. Software doesn't count, sorry! "Open source" in this case is strictly defined by the OSI Open Source License definition. Bizarre and/or restrictive licenses don't count.

Items in bold are available for sale to the public either assembled or as kits "Developer only" doesn't count

Projects must be at least started to be counted here!

• OpenCores Open Core chip designs
• Simply Risc Open Core based on OpenSparc
• Free Model Foundry FPGA models

• OpenServo a replacement control board for standard robotics servos

• RepRap 'self replicating' 3D printer
• Fab@Home 3D printer

• Monome 40h Open firmware/software general purpose sequencer. Layout and schematic are not open source.
• GlitchDesk Highly Liquid's patchbay (Product was available for sale)
• Daisy MP3 MP3 player
• Butterfly MP3 MP3 player designed with AVR Butterfly devkit
• x0xb0x Open source monophonic MIDI synthesizer (one of my projects)

• Balloon Board Open PXA270 based linux-y dev board (will be available for purchase soon?)
• Arduino Pedagogical physical-computing platform
• Chumby Open source linux/wifi/sensors device, available retail for $150
• BUG ARM platform with 'pluggable' extensions

• OpenEEG an EEG design that is OS & available as a kit or assembled
• Open Prosthetics CAD designs for prosthetics

• OS Car Open source car design
• TuxPhone Open cell phone design
• Open Graphics Open source graphics card (FPGA based)
• Wave Bubble Open source RF jammer (one of my projects)
• uC Asterisk Open Asterisk telephony project

• Simputer Commercialization requires purchase of a $25K license. Fails part 1 of the Open Source License definition
• Sputnixie Despite saying "Open Source" there is no actual license attachment, there is also a "non-commercial" string
• Neuros Open "Set-top" Digital Audio Player - Claims to be OS, but no real schematics or layout are available

• Open Circuits SparkFun's collection & project resource
• Open Collector Large collection of links
• Openhardware.de Somewhat empty (and abandoned?) site
• Open Hardware Foundation A nonprofit involved with the Open Graphics project, intended to raise funds for its development