Yahoo announced its new Placemaker web service at Where 2.0 last week. Placemaker takes unstructured data, extracts references to places, and returns geographic metadata — take a reference to Chicago in a block of text, for example, and it gives you the city’s coordinates and WOEID (see previous entry). Here’s some documentation; see Om Malik on the usefulness of location services, which puts Placemaker in some context.