Google has finally came to the rescue of service based companies like plumbers, carpenters, carpet cleaners. Today they released the "Areas Served" feature where you can select a mile radius and the specific cities you small business services. How this will effect the rankings is still unknown, but this feature is going to certainly go a long way for these service industrialize getting found in multiple cities, without having to spam Google with multiple records. Here is an article with illustrations: http://ezlocal.com/blog/post/google-maps-areas-served.aspx