(more pics at our Flickr website taken with these PVC snoots).
UPDATE: August 2013 - After two and a half years shooting with strobe snoots, I have realised the potential of them in underwater macro photography. I use what I refer to as a "semi-snoot" for almost all of my macro photography. I simply attached a PVC pipe fitting that reduces 3" pipe to 2" pipe (made for gutters on houses) onto the front of my Inon strobe (Z220), this is the same size needed for all Inon Z series strobes Inon Z240, Z220 and the D2000, D180 models.
The PVC fitting simply reduces the normally wide beam of the Inon strobes down to a relatively narrow beam, that needs to be accurately aimed at the subject.
It reduces backscatter, renders a dark back ground to most images (as the background isn't being lit by the strobe) and teaches accurate strobe aiming! It can be used to backlight subjects (as above) or for harsh side lighting (adds contrast), or to light just a part of your subject from a particular angle. Great for artistic effects in your underwater macro photography.
In July 2013 we also added a new Fiber Optic Snoot to our range of Reef Images Underwater Photo Accessories. The BluSnoot is a pair of flexible arms that contain fiber optic leads, these are attached to the head of the strobe and used to aim the strobe lighting at specific small areas of the photo, they are great fun to use and open a whole new spectrum of macro photography. Click on the Flickriver link below to see photos taken with the BluSnoots in the last few weeks.
More details at our Fiber Optic Snoots page and prices at our Reef Images - Underwater Photo Accessories page.