There has been much published about the use of shipping containers for architecture - be it the single unit or the multistacked construction:
What makes shipping containers ideal is their portability - and I think their ideal use would be to turn larger empty spaces into smaller more manageable units - sort of a reinterpretation of the factory to lofts idea. Transforming a warehouse into offices, as illustrated in the Inhabitat post on 9.29.09, shows the potential of the idea. One could take the remaining rust-belt infrastructure and transform it into a small business commune - shared facilities for kitchens and break-out space, and then smaller units for private offices and secure file storage/server space. This could also be used in defunct big-box retailer spaces in suburban areas. It sort of is an american scaled version (we do like things bigger) of the ideas of the LynFabrik in Aarhus, Denmark. LynFabrik is a shared space for creative professionals - the building houses office and studio/workshop space, as well as a cafe all of which are designed to allow the intermingling of solo or small group creative practitioners - and the cafe is open to the public (though it is located on the roof, so it isn't overwhelmed, though it does stay busy).
I suggest you check out the Inhabitat article on MVP using shipping containers for its office, and think about all of the possibilities...
Some images from the project: