How to access files saved in a virtual box?

"If your VM is running (suggested method)

You can use the Shared Folders (after installing the Guest Additions) feature of VirtualBox to expose a folder on the host operating system to Ubuntu.

You could also use some sort of network transfer from the guest (Ubuntu) to the host provided the host is running something like ftp or ssh.

If you VM is not running (untested)

Consider mounting the hard disk image of the guest directly, http://forums.virtualboxdotorg/viewtopic.php?t=4748"