A group of students at Germany's Hasso-Plattner Institute have developed the Protopiper, a handheld device that takes packing tape and "extrudes" it into rigid tubes (presumably with the sticky surface on the insides). It's meant to allow the user to quickly bang out 3D wireframes of large objects, like this:
While the resultant extrusions obviously lack load-bearing capacities, I'd imagine this would be useful for exhibit designers or furniture designers trying to rough out scale. And the real brilliance of the Protopiper is how "lean" it is. If you think about the materials you'd typically use to produce large-scale mock-ups—cardboard tubes and connectors, 4x8 sheets of foamcore, and the tools required to cut and shape those items—then contrast that with traveling to the site with just a Protopiper and several rolls of tape, it's easy to see which is more efficient to tote.
Enter a caption (optional)
Assuming you're traveling locally, that is. Try bringing this through an airport and you're getting dragged into that little questioning room for sure.
A detailed, downloadable PDF showing and explaining (in English) how the Protopiper works is available here.