Best way to implement command line uploader in my webapp

I have been researching a lot different options for multiple file uploaders to implement in my web platform and provide comfort to my users. My main concern is, that I wouldn't like the UI to be blocked, while user is waiting for 0.5 GB to go up. So I now came up with an idea after I popped in to a few articles:

Would it be possible from the web browser the user to select his files for upload. Then the paths to be cached and a separate program to start uploading them in background, outside of the browser using command-line upload. (something like that: http://chunk.io/)

How realistic this is and how smooth I can expect it to be for the user? Is somebody else doing it like that, or this is too overcomplicated? Can I prevent the command-line window to appear and so on...

Thanks in advance for your thoughts!