Rainworks is perfect for creative personalities or budding artists who want to send out positive vibes into the world. Users can spray a message or stenciled picture on a sidewalk using Rainworks, wait for it to rain, and voila — your art is there for all to see! Funded on Kickstarter, the eco-friendly spray works for about two months. Be sure to take a snapshot of your work and email it, along with a precise location, to the company for inclusion in its Rainworks locater map, and you'll be credited as the creator! Rainworks Invisible Spray began preshipping orders this month.