We, in the OSHW community, don't spend too much time thinking about patents. We'd rather be making. Not to mention, the idea of disallowing others from using your designs goes against the Open Source ethic.
But, by stifling innovation, patents have had a huge impact on the open source community. Often, companies refuse to make public details of their hardware and software programs (details that would be invaluable to open-source enthusiasts seeking to, for example, create open-source drivers for proprietary hardware) because of fears that they are accidentally or knowingly infringing on the patents of competitors, and that publishing such details would expose themselves to expensive lawsuits.
One innovative response to recent ongoing patent wars is the Defensive Patent License, or DPL (an homage to the GPL free software license). The DPL is a legal mechanism to protect innovation by bringing together patent-holders in a network. Participants agree to license their patents, royalty-free, to all other members of the network, and in exchange receives the same licences from other users’ patents. Everyone in the network is forbidden from using aggressive patent litigation against other members.
A recent discussion on the hackerpaces listserv might be leading some in the OSHW community to join the DPL. Matthew Senate of Oakland, CA-hackerspace Sudo Room has also suggested the creation of a "DPL design challenge" (which, in typical open source fashion, was immediately made into a web call-out by another list user) - a system by which makers can impliment prototypes of patents listed under the DPL as a form of active participation in the network.
The DPL plan has been kicking around since 2009, but is finally scheduled to be released in November at a kickoff event in Berkeley.
If all this patent stuff sounds like gibberish to you, a good explanation of it all was published by Network World in 2009.
InMojo supports the Open Source Hardware Definition v1.0