I've always associated oxyacetylene torch with the brutish but necessary industrial activity of welding but never art. Well, the resulting metal thingy may be an artistic sculpture, but the acts of cutting and welding themselves be art?
Here's a video clip by benderautomatic over at SuicideBots blog that's aiming to prove that metalwork itself is a kinetic art: http://www.suicidebots.com/2010/09/10/oh-yeah-baby-drag-that-tip/ [embedded YouTube]