Well, I don't know about matrices, but The Matrix trilogy should definitely be in a class of its own.

Actually, I find matrices to be pretty lame myself, but they're used quite a bit with 3D graphics and animations. They're handy when you need to solve multiple equations with multiple unknowns that are all related.
For example, if there were three cool features in our game and I couldn't decide which one should have highest priority, I could turn that into a 3 by N matrix that contains all desirable qualities. If I then performed Gauss-Jordan elimination on them, I'd know the exact priority of each feature. Usually, I just do all that in my head since it's faster than writing it all out.

You can also do it in reverse, which is how I take someone's massive blob of feedback and turn it into specific and individual issues or non-issues. Again, it's much quicker to do in your head than on paper.
