When and how did the time zone system originate?  It seems to me that
until air travel (ie fast travel) or telephones (synchronous
communication) existed, there would be no need for it.  Who "invented"
it and what was the process for getting everyone to agree?

worldsaver,

Thank you for your very interesting question regarding time zones. 
time has always been dependent upon the position of the sun in sky
with sundials determining the time.  With the advent of the mechanical
clock in the Middle Ages, cities and towns would set their clocks
based upon the position of the sun.  This caused variances in times
from town to town, nevermind state to state or country to country. 
The first country to establish a Standard Time was Great Britain.  As
with most inventions or standards that have to do with time, the
railroads were the forerunners.  The idea of a standard time is
credited to Dr. William Hyde and was popularized by Abraham Follett
Osler.  In 1840, the Great Western Railway began running on London
Standard Time.  By 1847, almost all railways were running on LST.

The time zone standard used today uses 24 meridians of longitude
(lines running from the North Pole to the South, at right angles to
the Equator) 15º apart, starting with the prime meridian through
Greenwich, England.  This format was developed by Sir Sandford
Fleming, a Canadian railway engineer, and was presented at the
International Prime Meridian Conference in Washington, DC in 1884. 
The conference was attended by 41 delegates from 25 countries.  While
the time zones had been established, not all countries immediately (or
EVER0 adapted them.  They were law in the United States until Standard
Time Act of 1918.  All of China (which should span five time zones)
uses a single time zone. Russia adheres to its designated time zones
although the entire country is on permanent Daylight Saving Time and
is an hour ahead of their actual zones. Australia uses three time
zones - its central time zone is a half-hour ahead of its designated
time zone. Several countries in the Middle East and South Asia also
utilize half-hour time zones.

Thanks again for your question and I hope the information I have
provided is helpful.  If you need any further clarification, please
let me know.

Regards,

-THV

Search Strategy:
History of Time Zones

References:

WebExhibits - Daylight Savings Time
http://webexhibits.org/daylightsaving/d.html

Time Zones
http://geography.about.com/library/weekly/aa030899.htm

Greenwich Time: Time Zones History
http://greenwichmeantime.com/info/time-zones-history.htm

Meridian Conference
http://greenwichmeantime.com/info/conference.htm

You may also like to read how longitude was "invented" or discovered, 
and its impact on time zones and the Greenwich meridian itself in a
book called LONGITUDE by Dava Sobell from one of the South-Western
states. This is a book about one of the great genuises of the last few
hundred years who was about 150 years ahead of his time in regards
chronological technology. At 21 years of age he was able to build a
clock so accurate that it gained or lost only 2 seconds a month!! 
This at a time when the next best clock maker  could manage a clock
that gained or lost 15 minutes in day!!!

 This book is almost impoosible to put down once you begin reading it.
Of course you could see the telemovie which came out in 2000 at about
4 hours long as I remember; but as is often the case it is nowhere
near as good as the book