I won't be in town to help out, but i think it's a great thread so i did some research.
God's Love We Deliver
(212) 294-8169
http://www.volunteernyc.org/org/opp/2622708.html
We need volunteers to deliver meals on Thanksgiving Day. Some walking deliveries available in Manhattan only.
Marble Church (5th Avenue & West 29th Street)
(212) 686-2770
http://www.marblechurch.org/volunteer.html
--On Thanksgiving Day helpers serve turkey dinner to needy seniors and disabled persons through Project FIND.
**a friend told me that most churches have soup kitchens that need volunteers.
Meals on Wheels
http://www.citymeals.org/get_involved/volunteer/thanksgiving.html
--look at link for location nearest you (with phone number)
You can package and deliver meals to homebound seniors, as well as serve meals to mobile seniors at a local meal center.
The Bowery Mission
http://www.bowery.org/features/thanksgiving04.htm
1-800-871-6347 or go to the site above for volunteer registration
The Bowery Mission (227 Bowery) offers food, shelter, showers, and clothing to New York City's homeless.
City Harvest
http://www.cityharvest.org/
Throughout the year, City Harvest works to provide food to those in need throughout New York City. To make a donation to City Harvest's Thanksgiving Dinner program, please click here or contact them directly at (917) 351-8700.
--couldn't find volunteer info, but you can look at their website or call the # above.
Hope this helps!
Mindy