Insulation, Radiant and Vapor Barriers - Blown Cellulose, ceiling and walls?

I am about to hire someone to blow cellulose into our attic (after finally replacing all of the old wiring). I had considered trying to blow cellulose into the uninsulated walls but now I am having second thoughts. We have lathe and plaster on the interior walls and the exterior wood siding has been encased with aluminum siding. The only "easy" option is to drill 1" or larger holes into all of the interior cavities and then plug the holes afterwards.

What do I gain from insulating the walls? I know the attic is the most important along with good windows and caulking/sealing holes etc. Is it worth the effort to drill/patch all of the holes plus the cost of insulation?

I'm just looking for someone's opinion other then my own :).

-nalle

Well, consider this. The R-value of your walls with no insulation is basicly 0. The r-value with cellulose is about 3.8. Big change. You will definetly save a lot of money on your energy cost. The cellulose will also fill up all the small holes that are in your walls and help control the air movement. They might need holes larger than 1" tho. I would do it. Remember that old saying moms have?

"Close the door! What are you trying to do, heat the neighborhood?!"