Look for examples of simple web form designers

I have a requirement to implement a "simple" web form designer that allows "simple" users to create their own web forms. I've run into these things with rich clients like Outlook and Acrobat, but my requirements are much simpler and need to be web based.

Pretty layout, spot checking, complex fields and types just aren't a factor. Ideally, I would like to find something as neat as this very tricky question I'm currently typing in, and the ability to drag an input text field or checkbox right into the text. The output can be as crude as this:

What's your name? [Fred Bloggs]
Do you have internet? [X]

I am using asp.net but the backend technology doesn't really matter as I'm afraid it's all javascript! No need to consider older browsers. Any links to examples would be helpful, as well as suggestions for existing open source or commercial components. Thanks!