Get one million Rubiks cubes and arrange them in a square formation. Behind each cube place a contraption consisting of four push-rods which allow each cube to be turned and manipulated as needed. Add a computer to control the whole thing.
The RGB components of the cubes make up a giant tv screen (more like a dynamic mosaic actually) for public veiwing pleasure.
EDIT - title changed to avoid deletion-- simonj, Jul 31 2008 ahem. rubik_20cube_20tv_2e [po, Aug 01 2008] cool +-- xandram, Aug 01 2008 would it be visable from all four sides?-- letstopsmoking, Aug 01 2008 Nice - but looks redundant to me and therefore [marked-for-deletion] - see po's earlier version. Sorry [simonj] happens to us all.-- xenzag, Aug 01 2008 they're a bit dfferent aren't they? perhaps a change of title would be sufficient.-- po, Aug 01 2008 [xenzag] not the same idea at all.-- simonj, Aug 01 2008 [letstopsmoking] no, it's a flat square not a cube.-- simonj, Aug 02 2008 random, halfbakery