Anyway, very interesting!
Hello, my name is Martin O'Loughlin. I am an avid didgeridoo player and theoretical physicist. Over the past few years I have been experimenting various modifications of the didge and have finally come up with a new concept that I like a lot and that has led me to a "new" class of musical instruments. I call them the opendidge and you can find a decent amount of technical detail here
together with pictures and a pdf file containing an article explaining the acoustics and basic construction.
In addition I have put a video on youtube.