Convert VMware disks (.vmdk) to VirtualBox format (.vdi)

Extraido desde : http://codelab.ferrarihaines.com/archives/61

Although you can play directly VMware images in VirtualBox, sometimes you might prefer to convert it to a native .vdi image so you can use all the standard commands like clonevdi, etc on it.
Converting the image is quite straightforward:

1. Release and remove the VMware image from virtualbox's virtual media manager if the disk is already in use by one of your virtual machines.
2. Clone the disk specifying VDI as output format:

   brau>$ /usr/bin/VBoxManage clonehd image_to_convert.vmdk converted.vdi --format VDI --variant standard --type normal   Sun VirtualBox Command Line Management Interface Version 3.1.6 (C) 2005-2010 Sun Microsystems, Inc. All rights reserved.   0%...10%...20%...30%...40%...50%...60%...70%...80%...90%...100% Clone hard disk created in format 'VDI'. UUID: 84f005f6-bbf8-4a0e-9fe8-3b7bf0df14d5

3. Add your new vdi to your Virtual Media Manager. Now you are ready to create a new VM using the new .vdi disk

 add “–format vdi” to this command to make sure the resulting disk has the vdi format and not vmdm