Soooo agree with this article:

http://gojko.net/2007/12/04/waterfall-trap/

In my last project, we decided to follow an iterative plan (without knowing it had a name), focusing on the main features and not on details, just trying to close the entire worklow as quick as possible.

By the end of the second week of development we had the workflow ready (very ugly, with uncompleted forms, no ajax at all, a lot of bugs, etc).

The customer saw it and he couldn't believe how fast we prove his idea.

From that moment we started working on details knowing that we were on the rigth way and with a customer seeing improvements daily.

Everyone was happy from the second week.

At least for me.... it worked