Today, as I was watching rabbits, a man on a bicycle, a submarine, and the logo for expedia.com pass by as clouds, more or less, I was thinking that I had never seen a cloud in the shape of the letter B. Or a London double decker bus. Or Texas. And that's a something of a shame.

To address this, we can use high altitude bottle rockets, designed for the shape of the contrail they leave behind in the cloud layer. We could do all sorts of things, even, on windy - at high altitude - days, cloud puppet plays, with successive clouds acting out the plot.

I suspect it would get over-used for advertising, for example producing a giant bottle of Budweiser over a summer beach, or asking Jane to marry me, so we will veto such banal applications up front.