Want to surprise your Valentine with a cool gift that also reduces your carbon footprint on the world? The Ultimate Green Store, a Web site designed to teach customers about the importance of going green with their useful and stylish products, has everything from solar power chargers to decorative hemp collars for your dog. I have my eye on a heart charm necklace made by an environmentally responsible gold plating provider found in the Green Hot Valentine’s Sale section (hint to the boyfriend!). The best thing about the Web site? You can read under each description how the product you bought is making that carbon footprint difference.