laser cutting machine for cutting 3/4" thk. plywood etc for the woodowrking industry?

Yes I have seen one
This one is a huge monster that will cut everything from fabric to
at least 3/4" ply

This is an Industrial machine that can be custom built by RD Corp

RD Corp. Automated Laser Cutting Systems
#104, 11504-170 Street
Edmonton, Alberta, Canada
T5S 1J7
Bus: (780) 447-4312
Bus Fax: (780) 486-1306
E-mail: mailto:rdcorp@rdlasercutters.com
http://rdcorp@rdlasercutters.com

Henry Pel

Although smaller, you might take a look at
http://www.emissiontechnologies.com/
I haven't work with these, but they are very inspiring for a smaller scale.

Jason