Experimenting with different types of connectors, I would like to reduce the number of hardware fasteners required to build any one of a number of structures. This thing is a OpenScad file which can form a number of connection and vertex pieces. The connections and vertices are meant to receive a rod of a specified diameter (default 8mm). It is parameterized such that you can change various settings such as ball size, connector length, rod diameter, connection angle, and the like.

I am also going for an aesthetic. Basically, can hardware devices look artistically interesting while at the same time performing their function.

Files
Connectors have pass throughs on straight lines, thus allowing the rod to pass through them.

Vertices have butted ends in their connecting tubes, which do not allow the rods to pass through. Vertices are used as terminators on a structure.

Cube - Easily form cubes
Equilateral - An equilateral face, with a connector off the side to form a prism.
Tetra - Form a tetrahedron
Tee - A connector that is a T section

UPDATE: 30 Nov 2010
The Tetrahedron vertex is not quite right yet
UPDATE: 30 Nov 2010
New rodconnectors.scad
Tetrahedron vertex actually works now
UPDATE: 1 Dec 2010
Added Tetrahedron passthru connector. Nice for creating shelves.

1) Design your rod based structure
2) Cut your rods to the appropriate lengths (accounting for separation in vertex
3) Stick your rods into the sleeves of the various connectors

By default, the connectors take 8mm rods, but you can change whatever parameters you like in the OpenScad file.

Depending on which connector you are printing, you will likely need to print with support structure.