For a recent Drupal 6 project, we used Webform (http://drupal.org/project/webform), Salesforce (http://drupal.org/project/salesforce), and Salesforce Webform Integration (http://drupal.org/project/sf_webform) modules to create a custom form to send user data to Salesforce.com. Since the form was too long, we used the pagebreak component in webform to break the form into multiple pages. This not only improves the visual effects of a long form but it's also more clear when the form is made up of different sections.