Dropzone - If you want your file uploads to work even without JavaScript, you can include an element with the class fallback that dropzone will remove if the browser is supported.
Nubo - A self-hosted file sharing application in Haskell.
Yoink - Yoink is a website that makes it easier to drag and drop images and text from one screen to another. It's a straightforward site with help along the way if you aren't sure about dragging and how to place your content.
Box - Box offers secure content management and collaboration for individuals, teams and businesses, enabling secure file sharing and access to your files online.
Droplr - Droplr is a tiny application that aims at helping people share things easier.
4sync - A wonderful application that links all of your computers and mobile devices together. Easiest way to back up and sync your files online. Cross platform file management in the cloud