I\'m trying to create a web app based on ExtJS, and I\'m working on the file-upload area of the app.
I want users to be able to upload files by copying and pasting
I've seen that DropBox.com allows this to be done (in chrome- didn't seem to work in IE). I didn't do cut and paste specifically, but dragged files into a dropbox page from a local folder, and it uploaded the files. So, this doesnt directly answer your quesiton, but perhaps you can look at how this is done in their code.