where can I find a list of all the neighborhoods for all the US cities?

Question

Downloadable database is preffered.

Look:
http://en.wikipedia.org/wiki/List_of_neighborhood_listings_by_city

See the US section.
When you select one of the US cities, you get a list of neighbourhoods for the city selected.

This list is what I need for ALL cities, prefferably as a downloadable database.

Such a database must be several times smaller than a zip codes databases (which are for sale on every crossroad in the web), so I don't think that this is something like an attempt to "download the internet".

Any ideas on where can I buy such a neighbourhoods database?

Answer 1

http://www.city-data.com/

Answer 2

The Homeland Stazi Agency
The New FBI
They have some.