I see on Grand Central Terminal's website they have a new audio tour available...

http://www.grandcentralterminal.com/info/audiotour.cfm

First,(above) a short video I shot today which leads you in from near the 42nd Street entrance to Grand Central up to the audio tour window there...

The Grand Central website above will give you the lowdown on what their 100th anniversary audio tour will include..and I believe other tour options as well...

Thought it might be interesting toryn article here by Grand Central Partnership of what they call"The Grand Tour"

Tours

Step out of Midtown's rush and take some time to explore our neighborhood's iconic towers and hidden nooks.

The Grand Tour

The Grand Central Partnership offers a free, weekly, no-reservations-required, award-winning walking tour of the Grand Central neighborhood, that provides a survey of many of the architecturally and historically significant sights – among them the Chrysler Building, Grand Central Terminal, itself and Pershing Square – that fall within the boundaries of our business improvement district.
Come discover the architecture and social history of Midtown East with urban historians and tour guides Justin Ferate and Peter Laskowich. Participants on this 90-minute guided walking tour will learn the secrets of the Whispering Gallery in Grand Central Terminal; gaze upon the hubcaps and the roadsters on the side of the Chrysler Building; discover the favorite Midtown Manhattan hangout of Mercury, Hercules, and Minerva; learn why Pershing Square isn’t really square; circle the globe in a matter of seconds like Superman; and visit the original Lincoln Memorial by Daniel Chester French. It’s all right here in the heart of Midtown Manhattan!
Join The Grand Tour and experience familiar Midtown East landmarks like Grand Central Terminal, the Chrysler Building, and the News Building – through new eyes. The AAA Guide to New York rated The Grand Tour as New York City’s “Best Walking Tour.”
The Grand Tour meets each and EVERY Friday throughout the year at 12:30 pm in the sculpture court at 120 Park Avenue, located at the southwest corner of East 42nd Street and Park Avenue directly across from Grand Central Terminal. Again, no reservations are necessary.
If you’d like to take a tour of Grand Central Terminal, exclusively, there are number of options available via the Grand Central Terminal website, including an audio tour and a daily guided tour led by the Municipal Arts Society. For more information on either option, as well as additional group tour options, click here.
Note: Tours of the “behind-the-scenes” areas of Grand Central Terminal are not offered by our organization and are only rarely offered/authorized by the MTA.

TOUR DETAILS

SCHEDULE

Every Friday at 12:30pm

MEETING POINT

Meet in the street-level atrium at 120 Park Avenue, located at the southwest corner of East 42nd St and Park Ave directly across from Grand Central Terminal.

RUNNING TIME

Tour length varies according to the different content Justin and Peter include each week, but tours generally run from 90 minutes to two+ hours.

TICKETS

All tours are FREE and open to the public. No reservations are necessary.

Comments

Maria | March 28, 2013 at 8:56 pm

Will there be a tour on March 29, 2013…thank you
- GCPAdmin | March 28, 2013 at 9:22 pm
  
  There will be, Maria! There’s a tour each and every Friday at 12:30pm here in the Grand Central Partnership district.
  We’ve not had a tour on a Friday only once in the past five years, so…we’re on a roll!
  Should there ever be a cancellation of our tour or a change in time or frequency, we will be sure to note that on this page, immediately.
  Thanks for your interest in our tour and our neighborhood!
Dylan | March 22, 2013 at 4:10 pm

Are cameras allowed?
- GCPAdmin | March 27, 2013 at 9:30 pm
  
  Cameras are allowed, certainly, Dylan. Photography in particular locations you visit along the tour may not be, however, so keep an ear out for your guide to specify where and when photography is prohibited.
  Thanks for your interest in our neighborhood and The Grand Tour!
Lisa Gardner | February 16, 2013 at 1:00 pm

Can you please tell me whether Justin will be giving the tour this Friday, February 22? Thank you, Lisa
- GCPAdmin | February 18, 2013 at 11:06 pm
  
  Justin is one of two tour guides who give our tour every Friday, Lisa. His missing a tour in the 25 years (give or take) he’s been a guide for GCP has been incredibly rare, so – emergency aside – he should be taking one of the groups on the tour this Friday, February 22!
  Thank you for your interest in the tour and in Justin and we hope you have a wonderful time learning more about our neighborhood!
Jeff Sheldon | February 2, 2013 at 6:11 am

After having watched the NBC Nightly news tonight, experiencing Grand Central & the exuberance of Harry Kelly, this is definitely on the top of my travel list. And without having visited before, I imagine it what America exemplifies, its beauty.
Evelyn Mazur | February 1, 2013 at 2:04 pm

We will be in NYC May 26-31st.
Cannot make Friday tour of Grand Central.
Can you give any alternative suggestions?
Thank you
- GCPAdmin | February 2, 2013 at 9:07 pm
  
  Thank you for your interest in our neighborhood, Evelyn! There are a couple of great tour options, in addition to ours, that we recommend: the Municipal Arts Society’s tour and GCT’s self-guided audio tour. For more information about these other tour options visit: http://www.grandcentralterminal.com/info/tours.cfm.
  Thanks again, and we hope you have a wonderful trip to our city and neighborhood this May!
Joe | January 30, 2013 at 6:38 pm

Do the tours include walking through the glass walkway or a visit behind the clock?
- GCPAdmin | January 31, 2013 at 8:56 pm
  
  While our tour does cover Grand Central Terminal, it is focused on the neighborhood and all its landmarks (the Chrysler Building, Pershing Square, etc) more generally, and does not include the glass walkways of the Terminal or behind its Park Avenue facing clock.
  For information on ways to get a general tour of Grand Central Terminal specifically, visit: http://www.grandcentralterminal.com/info/tours.cfm.
  Metro-North’s Dan Brucker infrequently leads tours of the “behind-the-scenes” areas you refer to, but these are not widely-announced, typically, and sell out extremely quickly.