Ok here is my problem.
I need to be able to have a user drag multiple images from the locate file system onto the flash/flex/html5 app which will then taker the file na
Not possible with a web app in flash/flex - but you can do it inside air. It's basically a security issue.
As far as HTML5 - Only Firefox and Chrome currently support HTML5 native drag and drop events that I'm aware (Chrome would include some other webkit variants like safari)
Try this http://www.plupload.com/ It include all kinds of uploaded flash,silver light, gear, html 5 and html4.
As other people mention that drag and drop will not work for all browser. Limitation listed below.
If you are interseted in Applet try this.. http://jumploader.com/ Both control allow you to resize on client ( I know you haven't requested that)
For HTML5, see this great tutorial (browser coverage included): http://www.thebuzzmedia.com/html5-drag-and-drop-and-file-api-tutorial