Walking around NYC the last three weeks, The Death and Life of Great American Cities (Jane Jacobs) has been on my mind. In it, Jacobs describes what makes cities either vital & happening or dead & boring.
A key feature of some vital neighborhoods is short blocks. People utilize short blocks more frequently, all the restaurants, bars, & stores are located there (as well as some residences), and they just feel more alive. Really interesting things happen when blocks are very short and intersect in ungrid-like ways (like Broadway & 7th meeting at Times Square or all the odd angles in the West Village). Long blocks, at least in NYC, seem to be largely residential and unhappening, frequently feeling dead or even unsafe from a lack of pedestrian traffic.