The rig was built from "FoamCore" (about 3mm thick), and held together with masking tape.
Basically, it's a funnel slid over my EX580 flash, with a sheet of Vylene cloth stretched over the face of the funnel. This effectively produces a "Soft Box" to give a soft wall of light slightly off centre when shooting close-up and macros.
The effect of using this rig can be seen in the images below.
Plenty of light, and very soft shadows...
The first four images below were both using the flash rig, and are one exposure each. The bottom right two used available light, but consist of about 30 exposures each. The exposures, starting with the focus point set on the nearest part of the subject, and progressing to the farthest point, were then combined into a single image - all of which is in focus.