If I weren't stuck in Midtown right now, I'd be lunching on a tamale from Nixtamalito, a kiosk just opened by the owners of Tortilleria Nixtamal in Queens. It's in that plaza next to the Municipal Building on Centre St.
Here's a preview (with menu) from New York magazine: http://newyork.grubstreet.com/2011/05... . There'll also be a grilled-cheese sandwich vendor and a Hawaiian-style shave ice guy, among other things. Good news for downtown.
1 Centre St, New York, NY 10007