Orienteering Events in the UK in 2009 and 2010

Example of Bjoern Hoehrmann's OpenLayers Heatmap Layer

Data scraped from British Orienteering Fixtures list, grid references converted using PHPCoord.
Data is from registered events that included a grid reference, between February 2009 and February 2011.
Try zooming into your local area and use the sliders below to control the sensitivity and blob size of the heatmap.
Note: uses HTML 5's Canvas tag so does not work with Internet Explorer.