I think it was Rex who mentioned these before, it was in the automatic charging base topic.

DJ posted a few weeks ago about a navigation method they are working on which is similar in that it uses IR beacons and cameras to detect them so the robot knows where it is which is along the same lines. This is something I am eagerly waiting for more info on, it may just be what I need to get the motivation to get Melvin back on the workbench.

I saw it by Steve C on that topic having 40 pages. Still curious if anyone here has hacked the Rovio itself though.