On Sat, 15 May 2010 13:22:33 -0700 (PDT), js.b1 wrote:

The jigsaw would probably be best for thin cladding (shiplap etc), a
lot quicker than you realise.

The OP hasn't said what he intends to do with the cut wood. If it's
for a wood burner reasonably uniform size and few splinters is
desirable. Sawing would be the best, I used my table saw (and an old
blade) to cut down the shiplap from our shed refurbishment. That was
for the open fire.

If it's just to make managable for a bonfire, the quickest will be
snapping though over ones knee will probably end up with a bruised
knee fairly quickly. Much better to have a block on the ground a few
inches high and tough pair of boots and use your weight or a stomp to
break it up. I reckon that will be faster than a jigsaw and you still
have the problem of holding the timber.

--
Cheers
Dave.