Na i know the pottasium nitrate one as well (fertilizer right), but im pretty sure we used to make "weird arse" stupid crazy bombs out of Potassium Permaganate (in crystal form), in a jar, with some petrol. throw it at a rock and KABOOOM!!. by by rock.. but i may be mistaken.
Disclaimer - Do not try that little kiddies, actaully anyone, glass schrapnal is bad!!
PPS on a side note, did anyone ever get there hands on the "Anarchists handbook" on the net when they were little ones.. dam that was some crazy shit!