I came over this video and it made me think.. If this could be looped..
http://www.metacafe.com/watch/1890176/micro_mini_pulse_jet_2/
It's not my video, but it looks intresting.
I made a simpel setup drawing to illustrate the idear:
Attached jpg
Here is a even better vid.
http://www.metacafe.com/watch/1890348/jims_valveless_pulsejet_engine/
It looks like it would make a great shop heater.
Michael T