I've seen people on the net offering images of a particular Linux setup, and they offer it as either VMDK/VMX files or ISO files. Now an ISO seems to work with VirtualBox, because I can tell it to mount a CD/DVD drive and use the ISO instead of a physical drive, but the VMDK and VMX files are always listed as being for use with VMWare/VirtualBox.
So how do I use those files with VirtualBox? When I try the Appliance Import Wizard it tells me it only deals with OVF files.
(I'm using Sun VirtualBox 3.0.4)
VMDK/VMX are VMWare file formats but you can use it with VirtualBox: