MOMA
There were four Joseph Cornell assemblages on display as well as a few of his collages:
If you live in the NYC area, be sure to stop in and visit Seth and Kristin at the Cog and Pearl Gallery (190 5th Av, Brooklyn) I have several assemblage pieces available there right now (yes, a little shameless self-promotion).
Big street fairs seem to cover several blocks in different part of the city on the weekends...great fun if you get there early before the crowds of people show up: