The Biggest Font in the World

These letters are 0.92km high!

Source We also made an empirical estimate of spatial resolution for lower contrast vegetation boundaries. By clearing forest so that a pattern would be visible to landing aircraft, a landowner outside Austin, Texas (see also aerial photo in Lisheron 2000), created a target that is also useful for evaluating spatial resolution of astronaut photographs. The forest was selectively cleared in order to spell the landowner's name 'LUECKE' with the remaining trees (figure 10). According to local surveyors who planned the clearing, the plan was to create letters that were 3100 ´ 1700 ft (944.9 ´ 518.2 m).

A commenter at googlesightseeing.com calculated that the font size is 1.468.800 :) Google Earth *.kml link