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!
Cores (Chip designs)
a replacement control board for standard robotics servos
Open firmware/software general purpose sequencer. Layout and schematic are not open source.
Highly Liquid's patchbay (Product was available for sale)
x0xb0x Open source monophonic MIDI synthesizer (one of my projects)
Open "Set-top" Digital Audio Player - only firmware is open. Schematics are not.
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
Projects that are NOT open hardware