Functionally, they can offer added protection for your grille, headlights, bumpers, and hood. They can serve as a place to bolt auxiliary lighting, and some can even mount tow hooks and a winch. They are offered in black, chrome, polished alloy, stainless steel, and powdercoated colors. They can enhance the look of your vehicle, and chicks dig 'em. We're talking about grilleguards.
Whether you're looking to protect your vehicle's frontend from errant cacti and shopping carts, or just going for that look provided by a heap of sculpted metal on the front of your rig, chances are there's a company out there that has a bolt-on grilleguard that will fit your needs.