Lee Davis has a recent post to his blog showing how you can combine the Zend_Form component of the Zend Framework with Doctrine to help directly "drive" your forms.
On a few of my previous projects I found myself creating more form classes than I'd like. And after the 30th one I figured there had to be a better way. I quickly realised that most of the elements within these forms shared similarities to the data type I would use on my database definitions. As I was using Doctrine at the time I figured I could not only drive my database from my mapping definitions, but my forms too.
He shows how post gets into more detail about using the project (configuring caching, other config options).
The project can be found here on github.