Resizing a VirtualBox virtual hard disk

Resize An Existing .vdi Virtualbox Image – EASILY!
Followed the steps from this article and from comment #12 from this one to expand a 50Gb vmdk into a 70Gb vdi:

1. Created a new VM and added a new 70Gb dynamic IDE drive.  (IDE is important; it didn't boot when I had it set to use the SATA controller.)
2. Use VboxManage to clone the original cramped disk into the new larger disk:
   VboxManage  clonehd origHdd.vmdk  newHdd.vdi  --existing
3. Start the new VM.
   My VM was a Windows 2008 server, and it worked fine when I simply expanded the partition into the new space.  My drive now has 70Gb!