Most photographers buy a wide-angle lens so they can get more of a scene into the photograph, and that is a valid reason for getting that lens. However, there is more to a wide-angle lens and I want to offer one idea that can help your photography take a step up in creativity and impact.
Consider this a mantra as you change focal lengths: Go wide and get close.
What happens most of the time when photographers go wide? They go wide and either stay in the same position or they back up. They want more, more ... "Give me more power, Scotty!" "I'm giving you as much as I got, Captain." Always the idea is to get more stuff in the photo.
Now think about this a moment. As soon as you put that wide-angle on, your whole scene gets smaller in the image. That's how it all fits into the composition. But the problem is that often everything is so small that the composition loses its coherence and structure. The viewer then gets lost in the final shot and doesn't relate to the scene.
By putting on a wide-angle and getting closer, you ensure that something stays big and recognizable in your shot. You often can then create a very dramatic foreground to play against a great background. Foregrounds often get lost in detail and texture when a wide-angle lens is chosen and you stay put or even back up. By getting close, you force the viewer to really encounter that foreground in an interesting way.
This also often gives you a chance to do some environmental portraits that show off more than just a subject or a scene. You can learn more about environmental portraits at my new blog, www.natureandphotography.com. Basically, this just means you provide an important setting to a subject, and again, this is often done best by going wide and getting close.
I know this is counter to a lot of things folks here about wide-angles. "They" (those awful they's) will tell you that you shouldn't use wide-angles up close, that you might get, horrors, distortion. Ignore them! Put on that wide-angle and get as close as you like. That will make for some very interesting photos.
The photos here are: top, Alabama Hills, Lone Pine, California; middle, Buttermilk Area, Eastern Sierras, Bishop, California; bottom, California poppy and goldfields in burned chaparral, Southern California.