Another whistle partytrick on Youtube, drone generation 
http://www.youtube.com/watch?v=3o0T57ePUsQ
Fredrik is a great multisntrumentalist check out his other video clips if you have the time. They are worth it.
http://www.youtube.com/profile_videos?user=FredFredrik&p=r
The homemade elephant ocarina and tagelharpa are wicked, so is blues on a saz.
/MarcusR
That’s clever, but doesn’t look too difficult. Unless I’m wrong, the red-topped gen is just a drone. He seems to be fingering only the green-topped whistle. (Oh, yeah, I guess you already said that). Still, I may rig up something like that from some of my seldom played cheapies. Looks like fun.
I’ll check out the other clips. Thanks!
Try the following: Tape the upper three holes of two whistles and play both together as tabor pipes. Work with the overtones. You can get a complete octave with three holes. It’s fun. 
Holy crap! That’s pretty amazing. It makes me wonder
if I could play my Lap Dulcimer like a dobro… hmmm
BTW, about that drone trick.
As far as I can see, the tune he is playing is (speaking in terms of D-whistle) in key E, and the drone gives note D. I thought before that the key of the tune and note of the drone should be the same, but it looks like I was wrong.
Can anybody explain what drones are good for what keys?
Erik the Flute Maker makes double whistles using two Dublin Susato.
They seem very funny, you can hear the samples in this page