Weighing in at a couple of hundred dollars the Linksys NSLU2 is a very tidy little NAS device. It's a small (three CD cases stacked) unit that holds a 266mhz PPC processor (underclocked to 133mhz), 40meg of RAM, two USB ports and one network interface. Linksys have fashioned together a Linux-based OS running Samba to provide a very tidy, home/home-office level NAS device that can be easily administered via a clean web-based interface.
The Linksys NAS connected to a 2.5" 80gig drive (click to enlarge)
Where the little box gets really interesting is its ability to be hacked in almost any direction. There is a large community of Linux hackers producing custom Flash images that allow everything from the addition of extra software packages to the installation of a full-blown Debian system on the tiny box. The hackers have cleverly got around the flash memory limits of the onboard hardware through a method known as 'unslinging', or more precisely the ability to boot and run the device off a connected hard drive. Coupled with this there is a raft of hardware hacks that range from the relatively simple (removing the underclocking on the CPU) through to the really difficult (boosting RAM to 256meg by soldering together RAM chips).