I've been integrating blueimp's jQuery-File-Upload scripts into my software. It's a really nice package. But I had to spend all morning tracking down a weird inconsistency in iOS. Turns out that even with the file upload form set to auto upload through javascript (so no need for an actual submit button,) Mobile Safari seems to require that button be present in the form. Without it the file picker won't even be clickable. Weird. And it doesn't throw any errors to Web Inspector so this was pretty hard to find.