I tried the chisel method - about took off an extremity with a wild swing of the hammer, still aches after several months. Two words: electric chainsaw. Like a hot knife though butter and very precise. It does however suck 12 amps from the outlet. Keep the chain tight and it can be maneuvered laterally with ease, just glide over the top until you hit your marks. Always cut so the chain is pulling towards the board and you'll never splinter an edge. I did a 5' blade in under an hour yesterday (including sanding) with my 16" saw. About the same price as a sawsall. Here's the one:
http://tinyurl.com/5g7q6
As I'm accident-prone (see above paragraph), this makes the wife VERY nervous, but it's my new favorite power tool. Hmm.. noise & flying chips or sparks, heat and smoke.. maybe it's a tie with the welder 
