To a lot of foodies and backyard cookers "barbecue" means "smoke kissed" meat. The succulent and flavorful meat just isn't quite right without a lick of hickory, oak, or mesquite. Smoke flavor in grilling and barbecue isn't too hard to achieve. You don't need a huge wood stoked smoker on a trailer like the super serious competition teams or even a specially built upright smoker. The only thing you really need is real hardwood.
Hardwood chips or chunks for barbecue are fairly easy to find. Watch the country roadsides to buy good dry wood in full logs or split. Wood chunks - about the size of a lemon - can be found in outdoor and cooking centers. And smoking wood chips can be found bagged in many supermarkets right along side of the charcoal. When buying make sure the wood is nice and dry and with little bark attached (bark and insects can emit unpredictable scents).
If you don't have a true smoker you can still add that real smoke flavor to your outdoor gas grilled foods. Smoker boxes are made to contain about a fist full of your favorite wood chips. The box controls the intake of oxygen to help keep the wood from burning too fast and, instead, smolder with a slow stream of flavorful smoke lofting up to the meat. The boxes come in lots of shapes and sizes. Some are even triangular to set nicely between grill grates or wedge next to a gas burner. Most all smoker boxes are short enough to fit UNDER grill grates to set next to or on top of gas burners. Place the meat directly in line with the flow of smoke (usually between the chip source and an open grill chimney.
The smoker boxes are an inexpensive addition to a gas grill and can also be used in charcoal grills to keep floating ashes down off the meat.
If you are looking to buy a smoker box look for the most solid construction you can find. Ideally a cast iron box will last the longest in the high heat and corrosion. Pit masters will bigger grills sometimes resort to using cast iron pans for long term chip boxes.
If you are only adding occasional smoke in your back yard gas grill you can easily achieve great results by constructing a simple "smoker pouch" out of heavy (or double layer) aluminum foil. Simply fold the foil into a makeshift envelope, add chips of your liking, and fold to seal tight. Poke just a few air holes into the foil to release the smoke and then set the pack under the grill grate and on top of the burner. For longer cooking time (like four hour ribs) you can have a second or even third "smoke bomb" set aside from the start to quickly toss under the grate after the first pouch smokes out. Discard the pouches when the grill is fully cooled. You could even soak half the chips in water to slow down the smoking process. BBQ masters will typically soak wood chips and chucks for at least 30 minutes before they put coals directly on hot charcoal to allow for a smolder instead of a sooty hot fast burn.
Wood chips and a smoker pouches can really help make your next batch of home cooked barbecue taste like the competition champ's. Experiment with wood varieties like hickory, apple wood, mesquite, and cherry. Avoid pine and resin heavy woods that can leave off flavors and never use pressure treated lumber that could give of toxic fumes.