Maybe this should be under 'Relativity and Space-Time', but I'm really in it for the geometry.... so I put it here.
Yesterday, I threw together a little C++ program to take a sequence of PNG images, consider them as a 3-D block, and view it all through a 4-D kaleidoscope.
Sadly, my hosting site is really sledding at the moment, so you may have trouble checking it out until they sort out their issues.
But, here's the idea... Take a hollow (but not wireframe) tetrahedron. Extrude it along an axis perpendicular to the three-space in which it sits. Now, look through one end and put an image-cube at the other end.
Here's the link: http://www.nklein.com/products/kchron/
(Things seem to have cleared up a bit with my hosting site now. Hope it works for you.)