ahh, a dremel tool with a cut off disk or a grinding disk works wonders. Just grind off one side of the pin, use a hammer and a punch to punch out the pin.
For me, this was the fastest and easiest way to shorten a chain because i already have these tools.
Chain breakers do work good, but like spad said, buy a high quality one from s.b.p.
If you get a cheap one, or try to modify one for a bicycle chain, it probably won't last long.