Swallow Cafe, Cobble Hill, Brooklyn
Update - they appear to have closed for good
In the very hip neighborhood of Cobble Hill is Swallow Cafe. It's in an old Middle Eastern restaurant space. I've been there a few times now and the latte is good and the atmosphere is nice. It's typically filled with regulars with laptops. They have some tables that are laptop-less though so I always find a seat. I wasn't aware that they also have locations in Bushwick and Williamsburg. There are many cafes in NYC and not all of them are good. This one is worthy of mention.
Swallow Cafe, 156 Atlantic Avenue