This is getting a bit of play in the blogosphere, but it's too good not to note here, too. C.O. Ruiz, a former helicopter pilot in Mexico City, took photographs of what he saw from the sky, and has now posted them to the web. They're all fascinating, but some -- like this photograph of the Mexico City megalopolis, or this one of a massive low income housing development -- are simply stunning. It's hard to select a favorite. The street market? The expansion of the city into the hills? Maybe the picture of the city taken from the rim of a volcano...