Lipstick Jungle is filming in studio at the Broadway Stages, Brooklyn.
Law and Order: Criminal Intent is filming near Riverside Dr and 107th St. They will also be filming at 3030 Broadway today. Both locations are in Manhattan.
Gossip Girl is filming in Upper Brookfield again (in or near Planting Fields Arboretum).
Also: All Good Things was filming at Seaside Park in Bridgeport, CT, no word on if they are back there today. (Thanks to Liz for the tip!)
UPDATE: They are at Seaside Park today!