Smoking planks are fast-growing in popularity as a grilling accessory, especially in the Northwest where the Salmon come cheap. The use of smoking planks was actually devised by Native Americans of the Pacific Northwest to cook fish over an open fire. In modern times, smoking planks are being used all over the country to coo salmon, even in high-end gourmet restaurants.
These planks are usually untreated alder, cedar, maple, hickory, or mesquite. They char while cooking over the open flame which is similar to traditional smoking woods, but it imparts a more subtle flavor to the fish. Since the planks are soaked in water beforehand, the moisture in the wood allow the meat to retain it's moisture and to not dry out over the holy fires.
There are two main types of smoking planks: heavy-duty thick planks that are designed for repeated use, or the thin planks meant only for a single grilling.
How to use smoking planks
Soak the planks in water for at least 2 hours. Once your grill is hot, brush both sides of the plank with olive oil and place it down over the holy fires. Heat the plank until it begins to smoke, then flip it over and place your fish on the plank. Close the grill and cook until the fish is done. Planking cooking will often take longer than direct heat grilling since the plank acts as an insulator.
Note that heating and preparation times for the planks may vary across varieties. Please consult the plank instructions or your local barbeque store for the proper methods. Smoking planks are available at most speciality barbeque stores, or you can buy them online at stores such as Northwoods Smoke or Cookoutstuff.com.