Starting today you can simply drag a video file and drop it onto YouTube uploader to start uploading it, instead of using the operating system’s file open dialog.
Gmail first got drag-and-drop support in April last year, then Google Docs got it a couple of months ago and today Google enabled this feature in YouTube.
The YouTube drag-and-drop uploader supports HD videos as well as regular ones, but has a file size limit of 2 GB. To upload larger files, you need to use the Java-based tool.
This feature uses HTML5 APIs, so you need a recent version of Google Chrome, Firefox, Opera or IE9 beta to use it.