Why it works: Most people look at their flat wall and think, "What flat—or flattish thing—can I put there?" But objects, especially those that you might display on a bookshelf, can be an ingenious solution—in this case, it's a 1950s Lowboy model truck that belongs to a private collector of Fruehauf memorabilia.
Other options: Whirligigs, mechanical banks, soft dolls or old brightly colored seltzer bottles
How to try it: EBay and flea markets are obvious places to start; National Geographic's online store has Chinese terra-cotta statues, as well as handicrafts from countries such as Guatemala and Zimbabwe.
One last thing: Check the width of the object and make sure it can sit on a shelf no wider than 4.5 inches (any more than that and it will look awkward). Heavier objects need to sit on a shelf anchored to a stud in the wall. You'll want to avoid placing objects in high-traffic hallways, above a child's bed or anywhere they could be knocked over.