So, this is my first stab at coming up with something visual and it's in the same vein as Dewey Blobs…
…you'll need Java installed to view it.
Rather than lay Dewey out on a 2D gird, I'm using a 10x10x10 cube (000 is at the front-top-left and 999 is at the back-bottom-right of the cube). The code then cycles through all of the check-outs (orange) and check-ins (blue) from a single day, with a zigzagging 3D line linking up the previous transactions.
What I originally wanted to achieve was to have two curving lines, snaking their way through the cube, but figuring out how to do the Bezier curves made my brain hurt Anyway, if you want to see a version where the line runs more quickly, click here — it's harder to read the book titles, but the lines fade away more realistically. Or, here's a 3rd version that doesn't include the Dewey classification or book title.
A word of warning: the Java might chomp away at your CPU, so I'm not sure how well it'll run on a slower PC.