It was happy family weekend in celebrity land....'Law and Order:SVU's Mariska Hargitay, her husband Peter Hermann and son, August Miklos, took full advantage of the winter thaw in New York (summer's here till next week) to enjoy the Tribeca Street Festival. Mariska and the baby got into the music and were jumping to the beat. The baby was dancing and shrieking with delight. Meanwhiler Jon Stewart, wife Tracey and son, Nathan also stroll through the Tribeca Street Festival on Greenwich St. Nathan seemed fixated on the balloons. Jon sang to and kissed his son. They must be reading from the same script here. And over on the left coast. Life's is just all good 'Cheers' for Kelsey Grammer with his wife Camille and his children during a stroll through Malibu, CA (its always summer in LaLa land). More pics after the jump