[pdkl95]

As Brooks said, "Plan to throw one away; you will, anyhow."

There is value in a prototype - even if you don't actually use any piece of the prototype in the final product.

[dagw]

If you're going to quote Brooks, it might be worth noting that he's had a slight change of heart on that point: http://www.wired.com/2010/07/ff_fred_brooks/