I love mobiles, I always have. They're fun, they move, and they can add a lot to a room. Plus most mobiles you can easily make, which gives you the flexibility to change it at any time. You just need a few materials on hand. Before I start, check out these beauties:
garlands, bunting, and in this case - mobiles. Here's the link to the original tutorial where I first saw this: DIY Modern Colorful Mobiles.