How about using real landscape pictures as your alphabet? An artist from Australia has researched satellite pictures from a well-known mapping site to find artefacts looking like letters of the Latin alphabet. There's also a geogreeting website for you to use the world's letters to convey your message, provided you stay with the simple writing systems :-)

Thankfully there are plenty of other glyphs in other alphabets for you to hunt the maps and continue creating these new kind of world alphabets. Typography at a whole new dimension: lots of fun ahead.

I'm pretty sure our OSP friends who are also into creative mapping would be interested...