I've been looking for this app, especially after I unloaded my land line telephone. No more faxes for me! I simply scan my documents using Scanner Pro and my iPhone, adjust if needed, and then e-mail, store on my iDisk or print.
I can scan one or more pages of any size and then combine them into a multi-page PDF document to share. Allows for vertical or landscape layout. Editing features include correcting for color, brightness and/or contrast. I can reorder the pages within the document and even set a password for security.