Right near the NYU Law School, on Sullivan near West 3rd, and imagining that it gets a lot of traffic from the highly caffeine-dependent students over there, is Third Rail Coffee. It is so small that it's practically miss-able, but for the busy buzz inside and out. Tiny tables, tiny space, and no choice for milk - no skim, they just didn't have space for it or the desire to offer options, I suppose. They're nice about it, well, kind of curt, actually. But I just couldn't resist, and so I ordered a cortado (less milk) at their suggestion - they weren't above making a recommendation so I wouldn't leave sad and empty-handed.
Anyway, it's amazing stuff. Worth the stop; it's really one of the best around, in a neighborhood that takes its espresso bars seriously. Just don't plan on hanging out. The few tiny tables and places to put your tush will be all full up. Guaranteed.
Offering Intelligentsia AND Stumptown (and yet not enough room for skim milk, too?)