Fitting a 1TB into a box measuring 5.31 x 3.22 x 1.57 inches isn't all that easy (most NAS boxes we've seen would crush a squirrel easily) but Buffalo seems to have not only accomplished this but shoved in a whole bunch of other features as well. The Mini's got a Gigabit Ethernet port, support for RAID 0 and 1, Active Directory Support, UPS support (to shut down in case of power failure), and best of all, runs an on-board TwonkyVision DLNA server.
PlayStation 3 owners who want to shove a bunch of DivX/XviD movies onto a server to stream to their consoles for HD movie action will be thrilled. Less thrilling is the price: $699 in May. Those features aren't cheap, nor are the smaller laptop drives they use to power it. Then again, for about $699 you could also get a Windows Home Server, which is quite full-featured but isn't nearly as compact. On the third hand, we're not sure why you would need a NAS to be all that compact unless you were living in a tiny apartment or wanted to sneak it through customs. [Buffalo]