New NAS models are emerging surprisingly fast from Taiwanese manufacturer Synology. The latest is the Disk Station DS409slim. It's a four-bay barebones NAS, which takes 2.5in laptop hard disks rather than the usual 3.5in desktop variety. It isn't the first Disk Station to do so - it's possible to buy sleds for the two-bay DS209, which convert the 3.5in bays to 2.5in.