Shapeways - Shapeways - 3D Printing Service and Marketplace
Raspberry Pi - The Raspberry Pi is a tiny and affordable computer that you can use to learn programming through fun, practical projects. Join the global Raspberry Pi community.
3D Hubs - Airbnb for 3D printing
Arduino - Build your own electronics
i.materialise - i.materialise is an online 3D printing service, community and marketplace.
codebender - The Largest Arduino Playground In The World. Create, share and run your code anywhere.