We have a whole bunch of 4x5 dcg's, some of which I can throw your way if this takes off.
There have been several attempts to have a "roving show". I remember Joy suggested this to Kaveh some 5 years ago. The problem then, as now, is that people may not want to send their best holograms in case of loss or damage and the so-so or worse holograms may not impress the public too much. Also, very few, if any, seem to be actually making holograms. The "gallery" section is full of experimental stuff, but nothing that can be shown to the general public in a library.