Typomaps is an experiment gone product by German designer Dirk Schächter. You can order the world map made of letters (Helvetica Neue Black Condensed to be exact) in 100 cm x 70 cm or download both versions in different resolutions for iPad, iPhone or computer screen.
Typographic Maps is a similar project by Andy Woodruff, Mark Harrower and Ben Sheesley of Axis Maps (Texas, USA). The maps of Chicago and Boston, which took nearly two years to finish, depict the streets and highways, parks, neighborhoods, coastlines, and physical features of the cities using nothing but type. From a distance they can appear as accurate reference maps, and as you get closer you notice the thousands of words they comprise. You can order the maps in different sizes at Zazzle.