Well, color me impressed! I was just rooting around on the Autodesk 123D website, and I was fascinated by what I saw there.
The best way to explain this is by looking at this video. Suppose you wanted to design your own Arduino shield, for example. Using this online app, which runs in your web browser, you might start off using the virtual breadboard view.
At this time, the number of virtual breadboard components is a tad limited (more are being added as we speak), but this would be a great way to introduce beginners to using LEDs and resistors and switches and suchlike. (You can also work in a schematic editor view, which has many more components, plus you can easily add your own.)
Once you've placed the components on the breadboard, you add wires to connect them to each other and to the header pins on the virtual Arduino. Next you can enter an Arduino sketch, which you then execute and simulate on your virtual Arduino and breadboard combo.
Now, this is where things start to get really exciting, because there's also an intuitive and easy-to-use integrated printed circuit board (PCB) layout editor. This takes your virtual breadboard circuit as a starting point, but now you can specify the shape and size of your board and place the components and so forth.
Finally, you can actually order your circuit boards to be fabricated -- just a click of the mouse initiates the process to have your boards "professionally manufactured and shipped for free worldwide."
Actually, I'm not exactly sure what the previous sentence -- which came from Autodesk 123D website -- means. Does it mean that they will manufacture and ship them for free, or that there is some cost with regard to the manufacturing, but that the shipping is free?
Another really interesting thing here is that the folks at Autodesk are really working on building a community. Everything is free so long as you make your designs open-source and open hardware (if you want to keep your designs just for you, then you can choose a paying plan according to your needs).
Another aspect of this open-source and open hardware philosophy is that you can roam around the Autodesk 123D website looking at other people's designs. You can order any circuit that has been labeled as complete by the owner. Also, irrespective of whether a design is complete or a work in progress, you can fork that design, make modifications if you wish, and then order the PCB associated with it if you so desire.
All I can say is that this looks very, very tasty. As soon as I get a free moment I intend to play with this myself. In the meantime, if you've used these tools, I would be very interested to hear your experiences.
— Max Maxfield, Editor of All Things Fun & Interesting