There is also Hawk Ridge Systems
in Santa Clara.
However, no one I could find in Silicon Valley (or anywhere else) can touch shapeways.com
in cost, 3D printing tech and choice of materials.
Their Web site is light years ahead of anybody else.
You can upload your model, analyze / tweak it, see potential issues in a matter of minutes, choose material and see the cost right away, then "add to cart".
Most of the other 3D printing services still live in the "stone age" and want you to email the model and "ask for a quote".
By the time you'd get a quote from the other guys, shapeways would already have your part building in their 3D printer.
They can do SLS for plastic and now aluminium (We only use SLS. I refuse to waste my time with support structures).
But the real killer feature of Shapeways is that their software is orders of magnitude more robust than other services.
You don't even need to upload a closed manifold mesh! You can literally just stick the pieces together without doing a "boolean union".
This speeds up the iteration a lot.
I try using other services once in a while and much of the time they fail with a useless error message with the same file that I've already printed
fine with Shapeways!
No, I don't work for Shapeways and I don't get a commission.
We use Shapeways a lot for our robot etc. and I keep begging them to open a shop in the Bay Area...
At least they have a shop in New York now, so they don't have to ship from Europe...