Uploading is a very common task, in fact an almost daily task for seasoned website developers. However different browsers seem to have a very fixed way of displaying the form field element.
This can be very acceptable in many cases, I specifically love the way google chrome displays its file upload.
However there are instances where you wish to customize the look and feel of the file upload element as you can see on some certain websites that do have the typical file upload element (at least not to naked eye).
An example is linkedin, that small image button on the top-right corner right inside the text area itself.