Shipping containers have been a promising alternative to prefab architecture at least since Stewart Brand’s Sausalito research library. According to Gizmag there is now a Canadian firm called Honomobo that will drop one of these ready-to-inhabit home spaces on your lot for the price of a basic remodel.
Of course you’ll have to work out the zoning regulations with your local municipality. Other than that Honomobo units can be ordered with everything you need to live, from solar power to hot water and electric heating.
If you’re more of a do-it-yourselfer you can always buy your own shipping container (for $1200 to $5000 and up) and equip it on your own.