I have, and love, a Cameron Stovetop Smoker. This isn't a piece of equipment you'll often find praised, because what it isn't is a substitute for a proper outdoor smoker (or an indoor smoker with its own ventilation). If you want to make real barbecue -- a big hunk of pork or beef, or a chicken or turkey, smoked until it develops a smoke ring -- this is not the way.
Many people, like me, can't use a "real" smoker without considerable inconvenience (there are a couple places in my condominium development where I could use one, none of them near my kitchen) and don't have the means to install a professional indoor smoker. What's more, even a basic and not terribly great outdoor smoker is an expensive piece of equipment.
The stovetop smoker cost me $30. It comes with enough wood chips that most people will never use them up, and if you do, refills are cheap.
The way it works is you put it on your stove, put fine wood chips inside, put the tray over those, add your food, and close it up. The wood chips smolder, and after about twenty minutes begin smoking your food. The smoke alarm will not go off. Trust me, mine goes off during oven cleanings sometimes, while searing steaks, and so on, and the smoker has never once set it off. That's an improvement on the way I used to smoke things.
Essentially, your food is cooking in a small, somewhat moist, low-temperature oven. That's why it won't work for everything. This isn't an ideal cooking method for everything, and it's a pretty slow cooking method.
That's also the strength.
It's excellent for fish (I don't think I've tried shellfish yet). I love using it for smoked meatloaf. It's great for cooking potatoes in the smoker and then mashing them to make smoked mashed potatoes -- though the potatoes take 2 to 3 hours to cook, rather than the 20-30 minutes if you simmered them.
But some things benefit from a slow cooking time. I'm able to smoke butter -- I just put it in a small pie plate and put the pie plate in the smoker tray -- because it can sit in the smoke for a long time before coming anywhere near to burning. Fresh mozzarella will take on some smoke flavor by the time it starts to melt.
And grits ...
Grits apparently benefit tremendously from a slow cooking time. Not only does the combination of smoke and salt give them a bacon-like appeal, but cooking slowly -- these took three and a half hours, maybe four -- makes them silky and luxurious without being mushy. Ridiculously good.
I cooked 3/4 cup grits in 3 cups of water in the smoker, with just a little homemade celery salt for seasoning (I make crazy good celery salt, it's a weird thing to take pride in). Once they were cooked, I added a pat of smoked butter, a little crushed red pepper, and a generous shredding of Pecorino Romano cheese.
The greens, well -- nothing goes better with grits than greens. These are turnip greens, collards, and Swiss chard, simmered for about four hours in plain water with two bay leaves. I then adjusted the pot liquor with a little demiglace (super-concentrated pork stock), Texas Pete hot sauce, that homemade celery salt again, homemade smoked turnip salt, and a dash of Worcestershire.