I am installing slate in my hallway. I have 5 doors ( = 10 door
jambs) to shorten so I can slip the tile underneith the door jamb. I
checked ebay for electric door jamb saws and found $150 on up. A
little too much to justify for my project so I went to Home depot and
purchased one of those offset handle flush cut hand saws for $15.
After the first door jamb I decided "SCREW THIS!". I took the saw to
the garage and removed the pin holding the handle on then removed the
wooden handle. I pulled out my dullest sawsall blade and snaped to
about 2" long in my vise with a hammer. I then welded the broken saws
all blade to the flush cut saw where the wooden handle used to be.

SWEET!!!!!!!!!!

I took my new flush cut / sawzall blade and chucked it up in my
sawzall. I set the sawzall to a low speed (about 1.5 - 2) and it took
about 30 seconds per jamb.

I have decided to take out an "internet patent" on my new blade so if
you read about this on the internet and use it please send me $.50...
Ha... :-)

P.S. You could probabally drill the sawzall blade and bolt it to the
flush cut saw if you aren't blessed with a welder.