A friend on the Danish VMUG pointed me towards this simple backup script, from GestaltIT.com.
http://gestaltit.com/all/tech/virtualization/simon/vmware-backup-powercli-script/

The script creates a snapshot of a VM (from a CSV file) and creates a Thin Provisioned clone based on the snapshot, on a specified datastore (from the CSV file).

This a smart and simple way to create a backup of a list of VM’s.

It’s a must read for PowerCLI users.