How to make my Google form accept uploading?

(via PayableForm http://www.crazychro.me/gform)

Create a normal text field and put “(upload)” at the end of the question title. Like this:

It doesn’t matter if this field is a required question or not, nor at any page in your form. PayableForm will handle it for you. In your response spreadsheet, the field will be a clickable url.