I've had more than one person tell me that if you can smoke up some good salmon, that you can smoke a darn good turkey too! Don't konw how much truth there is to this

but i'd say do a search on it. You're bound to come up with tons of brines for fish, that you could probably use on a turkey too if the above saying is true? I'd probably add a few more spices in there for a turkey though just to flavor the meat a little.
Did a quick search on YAHOO and came up with this...sounds like it would work.
SMOKED TURKEY
1 (10 lb.) turkey, thawed
2 c. salt
1 c. brown sugar
1 tsp. pepper
1 tsp. onion powder
1 tsp. garlic powder
1 tbsp. red hot sauce
6 drops liquid smoke (only if you weren't going to smoke it with chips)
Mix all ingredients (except bird) into a porcelain pan. Fill with enough water to cover bird and mix well. Add bird to brine and weight down so bird is totally covered.
Brine bird for 8 hours in a cold spot. Remove bird and drain (do not rinse). Hang on hook in smoker for 4 hours. Remove from smoker and place in oven at 350 degrees. Bake 2 hours. Cover with foil and bake 2 more hours or until bird is done. Serve hot or cold.
Hope this helps a little.
-jokester