Thanks to some great work by Takashi Beppu, Pierre and Gerwin Sturm in the comments sections of this blog we now know what all the letters spell in Google's Treasure Hunt.
There are nine separate treasure trails that you can follow on Google Maps' new Treasure Map. If you get to the end of each trail you will find a red symbol in the shape of a letter. You can also find this cartographic data in google maps met streetview and World Robinson Projection map, Adobe Illustrator, download now maps vector clipart. If you haven't got time to follow all the trails then check out this Spoiler Map.
The map is an animated slideshow that reveals each of the letters in turn. All you have to do is sit back and try and spell out the two words that are revealed.
If you interested in how Google created this map then check out this video, starring Google Maps Mania's own original blogger, one Mike (the peg-leg) Pegg,