I still didn't finished my Prusa I3 but I can say that I'm almost there - after almost one year now it's just a matter of a few adjustments/regulations and then I'll be able to print my own wissle.
And now, I just decided it, I do want to build one simple 3D scanner. I decided to build one after I saw this KickStarter printer: R-360.
I loved the idea and the size is really cool for small apartments. My bench is already filled up with stuff that my wife wanna throw away, GOSH! I need more room to my stuff! One of the most interesting features are the ability to install one "3D Scanner" kit and a plotter.
I don't like the online service idea - I think that a software like Repetier would be good enough. The online 3D library is awesome tought.
It's sad that they didn't reached their goal - now we will have to dig the web to get the details of this gadget in order to try to bring it into maturity.
KickStarter.com is awesome, I love their projects, I love the idea to invest into gadgets and toys that you like. There is one catch thought, IMHO, they have the tendency to support mostly (again, IMHO!) "professional" projects. IF you don't sell yourself they will not help you with that - even if you do have one awesome idea ...
A while ago I saw another project at KickStarter - the Peachy Printer. One US$ 100 printer. The catch is that this printer is not complete - you will have to spend some money into the resin container.
And the 3D scanner? It's here, the SpinScan. The project is a work in progress but it's super cool.
There is one alternative idea using encoders to point where you want the vertices but I don't know none open source project implementing it. Take a look here for details.