Fast Feedback

At a recent visit to the Science Museum, I spotted this at the 3D printing exhibition:

"With traditional manufacturing a lot of preparation time is needed to make a new part; sometimes special tools need to be developed and built. 3D printers require little preparation and no special tools. We can test our designs and make changes much more easily. This speeds up our design process and lets us experiment with new ideas."
3D Printing: The Future of Industry (PDF), the Science Museum

I thought this was pretty cool. For me it describes why fast feedback is so useful and it's pretty clear that the points apply equally to software.