A project I'm currently working to clean up a bit has some lengthy forms in it. They're already broken up a bit with CCK Fieldgroup Tabs, but I wanted to trim them down a bit further.
By theming the form elements, we can take the description of a field and use it as the title attribute of a small
image attached to the field. Then the user can hover over that to see the description, but it takes up much less vertical screen real estate.