This is, perhaps, a rehash of an older SO question "A html5 web app for mobile safari to upload images from the Photos.app?". I realize that iOS Safari simply does not permit file uploads. However, I was wondering if there are ways to leverage cloud storage API's such as Dropbox or iCloud so as to accomplish the same goal. So, for example, instead of a file upload dialog I would have a url that links to dropbox/icloud that could then prompt the user for the file to send.
Sorry if I'm being too vague - but I suppose I don't care too much about the mechanism of delivery.