Best free things to do in Poughkeepsie?

Walk across the bridge that goes over the Hudson River.  Great hiking in Mohonk Preserve and Minnewaska State Park (spelling is probably wrong!).  Vanderbilt Mansion National Historic Site and Home of Franklin D. Roosevelt are interesting - not too expensive.

The Frances Lehman Loeb Art Center at Vassar College is free.  The Samuel Morse House at Locust Grove Estate is free to walk the grounds; the tour of the house is $11. The Dia:Beacon is an art museum in Beacon, about 30 minutes south (driving, 20 minutes by train) ($15 admission, $7.50 RT train fare). Beacon also has a vibrant art and shopping scene along Main Street (a short walk from the train station). To the north, Rhinebeck has a charming antique district. And a little further north is Olana State Historic Site, the home of Hudson River School painter Frederick Church, with incredible views of the valley and Catskill Mountains. 

The newest experience in Poughkeepsie Poughkeepsie is the "Walkway over The Hudson" ... it is the longest pedestrian bridge in the world.  It goes over the Hudson River from Poughkeepsie to Highland (New York).  It is free and the views are awesome.  There is a charge for parking, but there is free parking available on all the surrounding streets ... all within walking distance.  There is also FDR National Historic Site Viewshed in Hyde Park which is right next to Poughkeepsie and the Vanderbilt Mansion National Historic Site.  There is a small fee, but the grounds are free to walk about.  The Culinary Institute of America is also not far and the food is wonderful, however can be a little pricey.