Windows: You've got easy access to a regular printer any time you need one, but not everyone has a MakerBot or other 3D printer on their desk. Windows app Autodesk 123D makes both designing and printing in 3D more accessible, with a simple but well-rounded design toolkit and options to save a project locally or get it professionally fabricated and shipped to you.
We've mentioned before how 3D printing can be a great way to replace impossible-to-find appliance parts; the app gave me an estimate of $US14 for this car visor clip. Wired editor Chris Anderson used the app to produce a small device housing for $US24. Unlike Autodesk's decades-old professional drafting and design software, Autodesk 123D beta for Windows is free, while Mac, iOS and Android apps have been promised in the future.
It works like this: open Autodesk 123D, design your 3D object using the surprisingly intuitive tools, and when you're done, click "Make It" in the right sidebar. Choose a 3D-printing project (the app also supports laser cut cardboard designs), choose your level of detail, and your model is uploaded to Autodesk's servers for processing. When those servers are done translating your model into something printable, the app opens a browser window with instructions and a cost estimate to have your 3D object professionally printed in one of four materials and shipped to you in about a week, depending on your location. If you do happen to have access to a 3D printer, you can save your design locally as an STL file to print it yourself.
Autodesk 123D might not be for folks who already have their own 3D printers, but for someone just investigating 3D printing, this app is a great place to start. If you don't want to start from scratch, the app also includes a gallery of stock and user-uploaded models, which they intend to turn into a market for users to buy and sell designs in the future. You can also import STL files you find on sites like Thingiverse.
Have you done any 3D printing, or have some unrealised plans this app might help you prototype? Let us know in the comments.