From BlenderWiki
User Coordinate Spaces (UCS)
Feature for Artists to quickly switch between coordinate spaces (a defined position, orientation and scale) allowing a faster and more precise workflow for modellers and, in particular, architects.
This is a useful feature for complex models where some of its parts are not aligned with the world's main axis and therefore utilities like the grid, background images for section blueprints and shortcut access (1/3/7) are not possible.
UCSs are not to be confused with 'Transform Orientations' that already exist, they are meant to be used in combination.
Discussion
Status
This project is not currently being developed as I am now full-time employed and no longer have time.
It is feasible and up for grabs as a GSoC idea.
