Tensegrities are a type of structural system where all of the compression members (poles/columns) are supported and connected to each other with tensions members (ropes). This means that the poles look as if they are floating in a mass of cables.
As promised, I am going to explain step-by-step how to build a tensegrity tower similar to the flagpole I made at Kontiki this year (shown here with the flag removed so that the structure is visible).
Tensegrity structures (the name means tension-integrity, because the tension cables are what makes the structure stand up) were invented by an American artist called Kenneth Snelson, who has made many tensegrity sculptures. R. Buckminster Fuller, an American inventor and engineer, named the structures after seeing sculptures Snelson had made.
Although they might look confusing, these structures are really very simple, and all that is needed is to be methodical when building them. I recommend building a model first, and this step by step guide will follow that format: a model, then a full-scale tower, and lastly links to some books and websites (and one or two other things).
Lastly, here are some photos of Kenneth Snelson's 1968 Needle Point Tower tensegrity sculpture at the Hirshorn Museum in Washington, D.C.