One improvement suggestion (although I don't know how difficult it would be to program) would be to have categories so you could display random pics from a whole category of galleries, not just a single gallery.
Nice idea, will have a look if a further version of the Smugmug flash applet may support this. My module is only a frontend to this flash applet for non technical users, the code is pretty basic. I have a new version in queue with Joomla! caching, and the resize bug solved (width is 220px fixed, on my site it is solved)