I bought a bright red bento box by Profile Design (Fuel Belt) for my Scott road bike. The bento box was to store an extra tube and some GU’s for IronMan, or a cellphone when out training.
I chose a large-sized FuelBox. It fastens onto your top tube with two velcro straps, as well as two additional straps which go around your head tube. You can see it on my bike in the photo at the bottom of the page.