I am back from NYC. I ended up buying a Spyderco Grasshopper from their "Slipit" line. It's a very small non-locking knife. While it has the Spydie Hole it cannot be opened one handed no matter how hard one tries; even if I turned out to be wrong about that it's still NYC legal when kept in a pocket.
The knife came with a wicked edge from the factory and was used almost constantly during the brief trip. For small cutting jobs it works admirably. I'm glad I bought it.
I've found that for urban use, a small, razor sharp blade is an excellent match. There's a reason yesteryear's pen knives all had ~2" blades.