I'm looking to build an Beacon, IR or otherwise, that a robot can see and simply drive to. Pretty much like a docking station for the robot to be recharged or a robot that follows you. (unless that's something different...)
I did a few searches, but I've only come up with robots that use a beacon and not how to build the circuit and write the code.
I don't know if this helps, but I'm pretty much looking to build what CtC did here: http://letsmakerobots.com/node/6499