The Oxford English Dictionary
or the OED
. It can be found online
now at http://www.oed.com/
. It is probably the largest example of a
Open Source collaboratively written book
. In the late 1800's James Murray
issued an 'Appeal to the English-Speaking and English-Reading Public of Great Britain, America and the British Colonies’. Thousands of volunteers contributed to it and it took 70 years to complete.
And guess what. They are doing all over again. In 1999 John Simpson reissued the appeal. Check out http://www.oed.com/readers/ to learn more about becoming an OED contributer.
Maybe you can be like Dr. William Minor who submitted thousands of quotations while he was locked up in England's harshest asylum for the criminally insane.