Heads up! This article was written in 2008. The theory itself is still good but the demos are currently broken. Static Maps API has URL length limit of around 2048 characters. You can hit this limit quickly when adding lot of markers. You can keep URL short by clustering markers together. Square Based Clustering Clustering is usually done by dividing map to squares. Square size depends on map zoom level. Markers inside a square are then grouped into cluster. This technique has some limitation...
