I'm a gas guy cause I have the patience of a 3 year old and don't like dealing with the charcoal. I do however offer a solution to bring some smokey goodness to your gas grill...
Here's a step by step guide...
Step 1: Purchase some wood chips from your local home improvement or BBQ store. They should have several varieties to suit your smokey pleasure. Right now, I'm on the Apple Wood kick. These bags run about five to eight bucks.
Step 2: Soak your wood chips in some water for about 20 - 30 minutes. Go ahead and light up your grill while you're soaking.
Step 3: Grab some drip pans that normally go on your grill to use as your smoke box. You can make your own smoke box using foil if you don't want to use these. 
Step 4: After your wood is soaked, place the chips in the drip pan and cover with foil. Cut a few holes to release the goodness.
Step 5: Place the homemade smoke box on your flavorizer bars or somewhere above the flame. Then give it about 5 minutes to start smokin'...
Step 6: Throw on your grub...In this case, it's a nice rib eye and some sliced zuke...
That is all there is to it. It probably takes about the same amount of time to do this than to get your charcoal grill going but I still am going gas. One of these days when I have a sick backyard to have several outdoor cooking devices I'm sure I'll have both. But while we're in team apartment, I'm on team propane.
