April Maker Challenge #8/30 : spaceCones

WHAT: cheap little modules that i can place like traffic cones, or suction cup, or whatever - that act like positional beacons. They should probably talk together to know where each is in relation to another.
Example1: 2 cones on the ground, and one fixed to my camera. with some calculation - i should be able to measure everything within this 3 pin area to the resolution of the beacons.
Example2: if i put 3 down on the floor, i want something inside it to be able to triangulate where it is in a given area. would be nice for position control.

OBJECTIVES: 3 cones (at least). they need to be able to judge distance from one another (i know there are rangefinders out there) . then they need to beam that information out to something else.

HOW: not a real clue in the world. i am guessing line of sight would be required for decent rangefinding - so i suppose IR data transmission would be an ok. it'd be nice if i can figure out how to do it otherwise.

APPLICATION: i was thinking of an alternative to CNC control where it is simply X,Y,Z tables. linear tracking is for suckas. If i can make all this wireless - and somehow have a paintBot.... then i should be able to print/plot on the scale of 100ft or so. (whatever the range and fidelity of the rangefinders would be)