There are many other woods, you can use. Don't forget the non traditional things such as walnut, grape vine, peanut hulls, corncob, nut hulls, and tree bark or some of these other "regional" woods: AVOCADO, BAY, CARROTWOOD, KIAWE, MADRONE, MANZANITA, GUAVA, OLIVE, BEECH, BUTTERNUT, FIG, GUM, CHESTNUT, HACKBERRY, PIMIENTO, PERSIMMON, and WILLOW.
Over the last couple of years I've experimented with using peanut hulls, and corn cobs. I'm impressed with both. I like to add a hand full of peanut hulls or two with pecan for pork shoulder if I'm not going to be adding a heavy sauce or no sauce at all.
The fun comes in when you start adding small amounts of the lighter woods to accent the flavors of your heavier meats and vice-versa. One hard fast rule is ALWAYS make sure your wood is seasoned otherwise you will get a very nasty ashtray taste. I also don't like soaking wood in water, as many will suggest. Really the only reason to soak wood in water is to cut down on the flair up and keep you wood from burning up and not producing smoke. My thoughts are, wood needs oxygen to burn, the less oxygen it has the less chance of flair ups and the more smoke you'll have. If you think soaking wood makes the meat your smoking more moist, you couldn't be more wrong.