Found some on youtube by searching “welding gas balloons”!
http://www.youtube.com/watch?v=9MQC2njRsQw
and
http://www.youtube.com/watch?v=a0PqmkKeNmc&feature=fvw
Impressive!
Don’t forget this classic dry ice bomb. Funny how the fat guy always ends up on the losing end...
http://www.youtube.com/watch?v=D7YudhnkCYk&feature=related