UK based art collective Greyworld have been making captivating public installations in urban space since the late 1980s. Their most recent project, 'The Game' turns London's Jubilee Gardens into an interactive birds-eye-view portrait of horror film director Alfred Hitchcock. Sensitive tiles on the ground trigger sound and imagery based on the proximity of visitors' movements. The space is intended for both interaction and contemplation, although collaboration with other patrons is important in order to realise the work's full impact. Their web site also documents their unique 'layer' installations, wherein sensors embedded in blue carpet-covered tunnels and bridges across the UK create sound environments based on foot traffic. Look around their web site, it's never a grey day. -Jonah Brucker-Cohen