Best new Flash 10 Feature: File Access

The new Flash 10 Beta is out. While all the graphical improvements are fantastic, for me the best new feature is file access. I've written a few applications where I wanted to load or save files directly from Flex. Having to write a server just to upload the file to and then send back to Flash was pretty ridiculous just to preview an image that the user may or may not want to really upload. As long as the user is asked to load or save a file it should be safe.