tokens: Indeed , I believe the best solution is to get a list of Craigslist sites/cities , prebuild a mapping of cities to coordinates using some geocoding API ( Tiny Geocoder comes to mind but Yahoo and Bing offer good solutions too ) , and then storing it in a way that makes sort-by-nearest easy ( say , MySQL 's geospatial extensions or MongoDB's ) .
ner_tags: O O O O O O O O O O O O O B-Website O O O O O O O O O O O B-Library O O B-Library I-Library O O O O B-Website O B-Website O O O O O O O O O O O O O O O O O O O O B-Application O O O O B-Application O O