Himmelstein was something of a pioneer in Local Search and worked for Internet start-up Vicinity Corp. Before being acquired by Microsoft, Vicinity was a provider of private label business locator, mapping, and Internet Yellow Page services (for Yahoo! among others).
Vicinity and early search engine Northern Light released Geosearch, which, according to Himmelstein, was "the first large-scale geo-enabled search engine." The project ended in 2002.
My gross simplification of Himmelstein's argument is that the future of Local Search resides in what he calls "Internet-Derived Yellow Pages."
Basically, he argues that current IYP/Local Search products are quite limited and the offline sources of structured data that most of them rely upon (to varying degrees) are similarly inadequate to deliver against consumer needs and expectations — and the true potential of Local Search.
He contends that the Internet itself can and should be organized according to local/geographic metadata (e.g., physical addresses) that reside on existing Web pages (he has an answer for the "but most SMEs don't have Web sites" issue).
The methodology that he's recommending for organizing the Web's unstructured content into a massive, structured local "database" (my language) would capture considerable non-commercial content that is inherently a part of local, but not reflected in most IYP/Local Search products today.
Again, this is a simplification and I encourage folks to read this provocative article.