There are 2 free Grand Central tours. There's one on Weds. that's just the building and on Fri. it covers a larger area. http://grandcentralterminal.com/info/historictour.cfm

There are some other listed here
http://nymag.com/guides/cheap/walkingtours/
although I'd phone and make sure since the info could be out of date.

The Municipal Art Society does some very good tours, not free, but not pricey. http://mas.org/tours/

March is awfully early for a guided tour of Central Park. You may luck out with a very warm day - but it's just as likely you'll have snow/sleet - and the trees don't even stat to leaf until late April.

I live in Boston so I know how to dress appropriately for cold weather.

I look at the Central Park tours website a little closer, and find out that only 3 tours are offered during my time in NY. They are:

Views from the Past tour
Cross Park Promenade tour
Amble through the Ramble tour

Does anyone have any opinions on the 3 listed above?

does any one know of any good architecture walking tours (of a specific neighborhood)? When I was in LA in December, there are guided tours of downtown LA, looking at buildings from the 1920s-30s era. Wondering if there's some equivalent in Manhattan.

Anyone?

Michelle Nevius is well regarded
http://www.walknyc.com/tours.htm
as is Alfred Pommer http://www.nycwalk.com/

Did I give you this self guided link
http://www.nyc-architecture.com/walks.htm

mclaurie - Thanks for the links. I did find the self-guided architecture tour website yesterday while I was Googling. The # of choices is a bit overwhelming, and I don't know how motivated I will be to do a self-guided tour. I'll look into it more in the next month or so.

Free podcast tour of lower east side:

http://www.lowereastsideny.com/podtour.htm