What is the lightest 155ish, all-mountain board on the market? 2003
or 2004 models any brand? I have checked out a lot of web sites but
none give the weights of the boards.

One thing to be careful about with very light boards - they may not
stand up to the punishment of freeriding as well as midweight boards.
Note that on Burton's site, they make it a point to warn you that rails
void the warranty on their ultra-light T6.

I have a 1999-2000 Salomon FRS. It's an extremely light (for it's
size, 165) BX board. It has the same hard ptex 4000 base as my "You
know who" boards do. However it dings up much easier... and so do the
edges. I believe that is the result of the core buckling from the
impacts, which in turn allows the edge to buckle and the base to cave in
somewhat.

So if you do get a super-light board, baby it!

Mike T