Rust. It's the product of metal oxidation, which we interpret as everything from a ruined car to a highly sought antique patina. And for this week's Shooting Challenge, you'll capture the beauty (or horror) of rust.

Primary colors—you probably haven't used them since some grade school art class. But red, yellow and blue are making a comeback in a major way. [ed note: they aren't]. Here are all of your best, primary color shots.

Red, yellow and blue. They're the most famous set of primary colors. And for this week's Shooting Challenge, you're going to capture them—all three of them—in one photo.

Neon signs are like looking at the future through the eyes of the past. They're incredible, often custom cultural artifacts all around us. And for this week's Shooting Challenge, photography an incredible neon sign.

Where were you last Monday? You know, Memorial Day? Some of you were kind enough to pull out your cameras and share the view.