For a true 4-dimensional Rubiks Cube, one that incorporates Time. Of course solving it will be incredibly disappointing, since after you do solve one, it turns out that it was solved all along.

Visualize our three dimensions as a bounded volume in 3-space. Then you can kind-of imagine the 4th and 5th spatial dimensions discreetly as 1- and 2-d arrays of such volumes.

I imagine solving a puzzle involving Time as a variable would be much like l'espirit d'escalier: By the time you figure out a solution, it's too late to implement it unless you can travel back in time 10 minutes. If you try to use your solution now, you're just going to end up making a fool of yourself.

While I can understand how that might be appealing to you, don't forget that the real point of puzzles is to have fun while exercising your brain. I just wish I still had all my puzzles from the 80's craze. I had the cube,the snake,the barrel,the pyramid,etc. But somehow they got lost through the sands of time. The only one I have left is this one [geocities.com] which I currently need to fix AGAIN,as my youngest nephew seems to think it's really funny to mess it up while I'm not looking.

But don't let the fact that someone has solved it already deter you from enjoying a good puzzle. After all it is supposed to be fun,right? And if it makes you feel any better I had to buy a book to solve the damned cube. I never had trouble with the others but something about the cube just never clicked right in my brain. I guess my brain just doesn't do squares.

The rubiks cube is one of those puzzles that's easy to do once you figure out the process. In fact, figuring out the process is really the only interesting part of the puzzle, and once you know it there's not much point to doing it anymore.