The Rubik’s Masterpiece, also dubbed “The world’s most expensive toy.” Created by Fred Cuellar, founder and CEO of Diamond Cutters International.
“Cuellar’s Rubik’s Masterpiece will be the centerpiece of the 40th anniversary exhibit. Valued at over $2.5 million, the fully functioning Rubik’s Cube required 8,500 man hours to be crafted in 18 karat yellow gold with 25 precious stones per panel set in invisible settings. Cuellar used 185 carats of rubies, emeralds, sapphires, and white diamonds to create the classic colored panels of the Rubik’s Cube puzzle with one small difference. While the original Rubik’s Cube is colored red, green, blue, orange, yellow, and white, Cuellar—himself a lover of puzzles and codes—decided to replace orange with purple for a variety of reasons both clever and protective.” (Full article at PRWeb)
Other oddities in the Cube world include Oskar van Deventer’s “Over the Top”, a 17 x 17 x 17 cube which was produced on Shapeways‘ 3D printer.
There have been some really tiny cubes made as well, also from 3D printers:
These 6mm wonders were made by Tony Fisher based on a Callum core.
Nowadays with software it’s possible to work puzzles of this nature in more than three dimenions and with insane matrices.
I loved my cube puzzles; I have a standard cube and a 2 x 2 x 2 mini-cube, and at one point owned a 4 x 4 x 4 Rubik’s Revenge which I sold on eBay recently because I could just never solve it. When I was younger I had more patience for such things. Puzzles of this nature were sort of like the “Angry Birds” of the 80’s.
The Old Wolf has spoken.
Playing in the World Game 
I solve the cube easily in about seven seconds but because of the high speed with which I turn it, relativity kicks in and moves the cube and me faster in time so that to the rest of the world in looks like just under two minutes.