Pentagram/London partners Angus Hyland and William Russell are the designers behind "Global Cities," an exhibition at the Tate Modern's Turbine Hall, which runs through August 27. An unusual blend of art, sociology and economics, "Global Cities" addresses the issues of size, speed, form, density and diversity as they apply to the teeming metropolises of Cairo, Istanbul, Johannesburg, London, Los Angeles, Mexico City, Mumbai, São Paulo, Shanghai and Tokyo. An earlier version of the show was seen at the 10th International Architecture Exhibition at the 2006 Venice Biennale, curated by the Tate, with data supplied by the London School of Economics, and art direction by Pentagram. For this London-based version of the exhibition, which juxtaposes comparative socio-economic and geographic data with the video and photography of 20 artists and architects, London-inspired work has been commissioned from the architectural likes of Zaha Hadid, Rem Koolhaas and Nigel Coates, among others.