Finding all VMs with thick hard drives

After a recent migration to VMware 4.1 and NFS datastores, I decided to convert all the hard disks of the VMs to thin format using storage vmotion. PowerCLI has a new parent property that makes it easy to get a list of the VMs using thick disks in a single line:

Get-VM | Get-HardDisk | where-object {$_.StorageFormat -eq 'Thick'} | select-object -expandproperty Parent -unique | sort