For higher rankings in Google Local, Yahoo! Local, etc., one of the primary proponents of the algorithm is the quality and quantity of listings your website has from local directory websites.  Below is a chart that lists the sources of local information to major local search portals like Google Maps.

Make sure you visit some of these and ensure your website/business is listed in the sources. Google, Yahoo!, etc. will ultimately pick them up and count them as a link/resource for your local listing.