Trulia has it, Ask.com has it (there may be others) and now Google has it: neighborhood search capability. The benefits and rationale behind this are obvious — aligning the capabilities of the engine to the way people actually think and live in the real world. It’s absolutely essential for real estate but also an important capability in the quest to improve local search.
From the Google Lat Long Blog post:
You can now do searches such as bagels upper east side new york and restaurants, over the rhine, cincinnati on Google Maps. Additionally, this capability allows you to do city-level searches where the city is uniquely named, regardless of size, such as bakery corpus christi, or movie theater albuquerque.
Among other improvements, Yahoo! recently added color-coded demarcation of neighborhoods to Maps, but in a couple of quick searches I performed in New York and the SF Bay Area (where the neighborhood maps have been introduced) the underlying data doesn’t yet seem to be “mapped” to those neighborhoods.
Unless Google has built this itself, there are currently two providers of this capability, to my knowledge, Urban Mapping and HomeGain.
Postscript: I’m also reminded by Yelp’s Jeremy Stoppelman that Yelp has had this neighborhood feature/search capability for a long time. He says they “may have been the first.”