File under: WANT. The ingenious folks at the sustainable product design and engineering shop called Studio Gelardi came up with this masterful lil’ tool for your bike. Seems as thought it’s still in ‘concept’ mode, but I can’t wait until it gets manufactured. Given the buzz it’s getting, I won’t be surprised if that happens soon.

Cool Hunting sez: “The small apparatus attaches to any bike’s seat tube and applies a thin layer of chalk powder in one of several colors to the rear tire. The result is an eye-catching streak that traces wherever you ride. In addition to visually enhancing the street, it serves as a directional guide for subsequent cyclists and a constant reminder to motorists that they should share the road.”