They might also be useful for grilling fish. I discovered this on a trip to visit my sister in Oregon. She used cedar boards to grill Halibut and Salmon.
She soaked the boards in water overnight, seasoned the fish heavily in a black pepper / sea salt / italian dressing merinade, placed the fish directly on the board, and put it over a charcoal fire. Very good.
I'm looking for a chance to try it on some of our southern cedar, if I can find one that needs to be removed. Saw many of them right after Katrina, but cant find one now. I want to cut it in disks and put some Redfish directly on the disks. I'll have to use a (hand) crosscut saw or Sugoi to be careful I dont get chain saw oil on the cedar, but I expect it to be very good.
In Portland, Oregon they sell cedar boards specificly for this purpose. Sis sent me some, "Jakes's Cedar Barbeque Planks" (100% organic, non-treated). They have some warnings on the back I will share with you. 1) For outside use only; do not place in oven; 2) Do not leave plank unattended on barbque grill; 3) When removing cooked food, wood will be extemely hot; 4) Use each plank only one time; and "WARNING: Wood Can Catch Fire".
According to something I read, this was a common way for the Northwest Indians to prepare fish.