You have an old gas barbeque grill laying in the yard; the burners are all rusted out and the grill is no longer useful. The framework is in really good shape, however, and you hate to throw it away. By re-incarnating the framework, you can develop useful things to do with an old gas grill.
You can make an outdoor cart. Remove the grill part, along with the bottom and the lid. Cut a piece of exterior grade plywood to fit the top, and attach with galvanized bolts. Conversely, you can cut lumber slats to fit across the top. coat the wood with a good outdoor sealer, and you now have an outdoor serving cart. If the grill does not have wheels, you will have to add some. Lawnmower wheels and hardware are readily available at most garden centers and building supply stores and are relatively inexpensive.
If the lower pan and the lid are still in good shape, you can convert it to a charcoal fired grill. Obtain an old grate or buy a grate at a camping store and place on the bottom of the grill. You may have to plug up the holes in the bottom with sheet metal if they are too big, since you don't want hot briquettes to fall to the ground. Fill it with charcoal one or two layers deep and use it like a conventional charcoal grill.
According to the California BBQ Association, you can make a smoker out of an old gas grill. This is done in one of two ways. First, plug all the holes in the bottom, but leave or make some small holes in the side (for air draw). Start a small hardwood fire in one corner and lay your meats on the grill not directly on the fire. Conversely, you can make a small fire box out of sheet metal, and fed the smoke up through the grill with stovepipe. If you don't have the tools or the time, a metalworking shop can do this for you.
You can convert the grill base into a garden cart. Take out the grill basin and the lid,and make a wooden top. Then, make some wooden doors out of plywood, and attach with hinges. Use a good grade of outdoor sealer and you can store small garden tools in it, such as trowels, garden spades, or small rakes.
You can use the base as a planter. Fill the old basin with potting soil, and plant seedlings. As an added benefit, if the base has wheels, you can roll it around, to catch the sun during different parts of the day.