Building features organically

I ran into this interesting post and wanted to share it with you:
http://marcelo.sampa.com/marcelo-calbucci/brave-tech-world/Building-features-organically.htm

This is how it begins:

One of the most interesting aspects of Agile development is to not build things
that you won't use now or over-engineer a component because "we might need this
in the future". That is a wonderful thing for developers and it does cut a lot
of complexity and time to deliver the feature, by consequence making it less
buggy.

Now, the rest is quite the same, so you can either go there or not.
But the first comment (and only one when I visitied) is pretty smart. And counting on you lazy fellows that you might not invest in following the link and scrolling down, here's what Mike comments:

I spec from the "top down" and build from the "bottom up". That way, I think I
have a more throught-out overall plan, and it eliminates implementing some
possible dead-end features. Specs are much more malleable and have far fewer
requirements from a quality point of view. So I find it worthwhile to be a bit
more expansive and "future thinking" in a spec. But when it comes down to
implementation, I try to do as you say - and build from the bottom up with the
minimum set of functionality that can be made to work consistently. You can then
decide when you've "fiddled" enough, and decide to ship the features to your
customers.

Well said.