Dietmar has a great post on where the images are located in APEX using webdav: http://daust.blogspot.com/2006/03/where-are-images-of-application.html He also covers how to access them via FTP!
I recently switched from Windows to Linux and was looking for a quick way to access the files as I would with Windows.
Using KDE and Konqueror, you can access them very easily. Use the following in the URL: webdav://<url>
So it would be: webdav://127.0.0.1:8080/i
Log in with system and you should be able to access everything!