Greg Sterling does the best strategic analysis that adds to understanding the big picture of Local Search. Two of his recent posts about Local Search that I found of particular interest:

•Yelp Becoming a CRM platform

•Local Numbers: Setting the Record Straighter

Bill Slawski of SeobytheSea also offers incredible insights on Local but from the technical viewpoint. His writings elucidate the technologies behind the scenes. His recently posted Google Local Search Glossary is a real gem.