The guys behind the very neat home servers sold by Excito, just started a kickstarter project for their private cloud solution.
This is so last year, or it will be when SAFE launches, but this little box might be a great choice for some always-on farming. 1.5W power consumption.
We have to get SAFE running on it first, which may not be straightforward - just ask Ross who is helping me build MaidSafe on the b3, the last box these guys designed when they were at Excito
Ubuntu based home server running ownCloud with 2G flash RAM and slot for 64G microSD that consumes 1.5 W just launched on kickstarter as OPI