Last week's techmail was Hack the D-Link DNS-323 to get an array of Linux server options. I bought one of these things quite a while ago to use more as a backup box than anything else (in case of fire, small NAS is easier to carry than big computer cases, etc.). But I had found the fun-plug stuff to hack the DNS-323 a few months ago and think it's great. Comments in the tip mention doing the same thing with FreeNAS on an old server... that's fine if one of your primary concerns isn't size, sound, and energy consumption. The DNS-323 works nicely in regards to all three, and it was pretty cheap to boot. If you've got one of these little devices and are looking for a way to unlock the potential just hiding under the surface, give the tip a read.