The Good Human's Prefab Wednesday discussed the Zenkaya prefab home from South Africa:

the home can be delivered in as little as 5 weeks.... [It comes] completely assembled, and all the owner would have to do is hook up the electric, the water and the sewer, and their home is ready to go.

Inhabitat's Prefab Friday covered the PowerHouse homes:

Our favorite, the “solar butterfly” roof design, collects rainwater, maximizes the use of daylight, and is fitted with solar photovoltaic panels to generate electricity - all for about $100,000!

Materialicio.us found a prefab kit called the casa ti, not yet in production:

The structure is framed in high-recycled-content steel, in SIP form. You can buy casa ti in kit form or buy the plans to build it from scratch. Prices for the kit start at $20,000.

Architecture.MNP showed off the BaleHouse, which uses straw bales for walls.

Treehugger looks back: Three Years Ago In TreeHugger: Prefab Crazy.