The micro fishing photo tank isn't exactly what I've been looking for, but it is awfully close. I've been looking for a suitable photo tank for a while now. There are some nice Japanese ones, but they are very expensive. A number of people here have made do-it-yourself tanks, and any number of plastics companies will custom make them, but I really wanted to find an off-the-shelf product that would work and be reasonably priced. This tank is the closest I've come across (and thanks to gunner48 on the North American Native Fishes forum for finding it).
A photo tank is very useful for getting a nice photo of your catch while keeping it in water so it can still "breathe" and won't flip out of your hand while you ready your camera. Additionally, identifying some species is much easier when their fins are spread - which they are in water and aren't in your palm.
The micro fishing photo tank really is micro sized. The inside measurements are just 3.5" x 1.5" x 1.5". There is also a hinged lid. It won't hold some of the larger species, but it will fit in your pocket.
(Please note: these are not professional, glass, distortion free photo tanks.)
I no longer sell the Micro Fishing Photo Tank. You can find it and the 3x5 Photo Tank at Angler's Emporium.