http://rotauf.ch/en
this crossed my internets awhile back and the principle seems to be an improvement on the old tie-a-colored-string-to-you-and-dangle-it-in-avi-terrain. But in inflates.
No replacement for everything else one could put in the arsenal but it does look interesting...
Anyone ever see one of these in use? Tested it yet? Hate the idea? Have other stuff to say about unrelated things?..