If the Rubik's cube is too easy for you, check out this puzzle created by Jason Smith of PuzzleForge, based on Andrew Cormier's design. Behold, the Petaminx, a dodecahedral puzzle with 4 slices per face:
It is entirely custom built and contains almost 1000 moving parts.
This project took place over two months, including:
20 hours on masters and molds.
12 hours casting parts.
30 hours cleaning up parts and sanding (!!)
7 hours assembling all 1000 parts
6 hours stickering.
Also checkout the video clip of Andrew Cormier's Teraminx - via Unique Daily
I am not a pro in mathematic. But I think if someone really would do a formula for the usual cube (which someone sure did) using it on a biger cube with more colours and more buttons/objects would be no problem for them ~him I guess. The reason behind mathematical formulas is exactly to solve such problems where you have so big numbers and so many different variables that you cant solve it succesfully with trial & error anymore ;)
if you want to check a nice collection check this one:
http://www.speedcubing.ro/18/colectia-mea-de-cuburi-rubik-8-iunie-2009