I use xscreensaver to view family photos, and often I wish that I'd
see more of the latest photos than all photos with equal
probability. How hard would it be to be to add two controls to
glslideshow:

  1. a sort order
  2. a curve describing the probability of selection of each image,
     which could be as easy as an exponential curve increasing with
     x being the axis listing all photos in increasing sort order.

?

It's just an idea, but I figure I should drop it here.