Miniature Mod allows you to shrink parts of the world and work on shrinked worlds using normal world mechanics. Shrinking does not stop e.g. redstone from working. The shrinked worlds can be rescaled to normal size any time by placing a rescaling block on it.
This mod REQUIRES the core and the patcher of the metaworlds mod which can be found here:
Install Miniature Mod 1.6.4
Download Miniature Mod 1.6.4