Shipping containers that were originally and currently used for over-ocean, over-road and over-rail shipment of bulk goods, and are now repurposed for residential occupancy and commercial storefront applications. This is especially useful in urban environments where space is more limited and the price of land is more a barrier to entry for prospective home owners and business developers. Shipping containers can be used as the main structure for efficiency dwellings or alternatively used as a basis of structure for contemporary architectural design.
Uses of shipping containers have extended beyond the typical purpose as freight containers on board ocean-going vessels.
Being an eco-friendly alternative is one of the main reasons why people choose to live in dwellings made of shipping containers. However, past uses of a shipping container may involve toxic chemicals, so proper understanding of its past use is as important as the methods to insulate residents from corrosion, temperature changes and other natural factors.
Shipping containers can be turned into portable factories. One example if this is one built by Re:Char. It was assenbled in the US and shipped to Kenya. It can produce ~600 Re:Char biochar kilns (cut out of 18ga mild steel) in a month. The design of the factory is open source (CC-BY-SA, specifically).
- Instructables - "DIY Factory"
Portable Power Plant
Here is a quick sketch: Charcoal/Steam Powerplant In Shipping Containers.
- Farm from a Box
- The Farmery - "The Farmery is a radical vision of what farms and grocery stores can be" (also see Cropbox)
Where to get them
- In Valencia:  New shipping containers (40ft) for around 2000eur.
- In Zaragoza:  , they also offer prefab houses
- In Barcelona:  They offer new and used containers (20ft to 45ft)
Free consultation availabe from these companies:
- Prototype Creation, Wiesbaden / germany 
Want a cheap, rough-and-ready shelter on your piece of land? A used 40 foot shipping containers costs about $2000. They measure 8 feet (2.44m) wide, 40 feet (12.19m) long and 8 feet 6 inches (2.59m) tall. That's an area of 320 square feet (29.74m2). Buy three of these, stick them together and you have something the size of a nice one-bedroom apartment that cost you just $6000.
One option is to partially bury the container for an underground house. You may need to put up a pillar or two to support the weight of the roof. Use a metal saw to cut out holes for windows, pipes, or stairs to the second floor.
Of course, a bare shipping container isn't a nice place to live in, but you can do it up however you want. You need to put up insulation and install electrical fixtures and other fittings. A bare shipping container will also look terrible from the outside, so you will want to cover it in recycled pallets, graffiti, plaster it, cover it with wood panels, or whatever.
- http://www.shipping-container-housing.com/ - This site has lots of information about sourcing containers
- http://home.comcast.net/~plutarch/ - Gives details of lots of projects of building using shipping containers