Here's the original "Squaring up to the Square Mile" G20 map: http://www.indymedia.org.uk/en/2009/03/425118.html
and these maps were produced before DSEi: http://www.dsei.org/wp-content/uploads/2009/09/dsei_city_map_websmall.jpg
and Climate Camp: http://london.indymedia.org/articles/1920Climate
respectively. Obviously, none of them are entirely suited to protests about education, but they're still better than nothing. Might be worth having a look and seeing if anything catches your eye.