No doubt you’ve run into this also…we needed a form handler that captured data for sObjects other than Cases or Leads (e.g. custom objects), we did not want to redirect visitors to a new page upon form submission, and our functional requirements were more complex than what the standard Salesforce form handlers could support. The standard Salesforce Web-to-Lead and Web-to-Case form handlers were not an option, so we had to create our own custom web form handler. And because we wanted to keep everything on Force.com, we decided to build this solution using VisualForce pages and an Apex controller served by Force.com Sites. We developed an alternative solution and wanted to share it with the community in the event it could help others.