As Open Design goes hand in hand with Open Innovation, you should have a look at https://www.quirky.com and https://ideapho.re. At both companies one can submit a product idea, and the community judges on it. If the idea gets promoters and members who support the project with advice, design and development skills, it may be choosen for selling to customer. If sold and produced all inventors (idea giver and supporters) will be rewarded for thier invention.
I’m personally searching for a start-up or company like these, which specializes in collecting module development ideas for Google’s modulare smartphone Project ARA, the modulare smartphone case Nexpaq and the modulare smartwatch Blocks.
If you hear about one, please let me know!