Picture ledges are a wonderful way to display a photo wall or home art gallery. Since placing framed art on the ledge doesn't require putting holes into your walls, you can easily change out and move around your art/photos as often as you like.
If you have children, try framing their artwork and displaying it along with your other pieces. It will encourage them to continue to be creative and it adds great personalization to your space.
Although photo ledge shelved can be found at several stores, I have found that Ikea has ledges that are very reasonably priced.