Google appears to be testing breadcrumbs in some search results, at least in some areas. If you are unfamiliar with the term breadcrumbs, it refers to the hierarchical display commonly used in site navigation. For example: Home Page>Product Page>Product A Page.
Several bloggers have noticed Google displaying these types of breadcrumbs in various places in seemingly random results to some queries. For example, Rob Hammond provides the following screen shot:
Leo Fogarty provides another, which shows the breadcrumbs displayed in a different position within the search result:
Google’s use of breadcrumbs appears to only be a test, and a limited one at that. Google has talked repeatedly about sites having good site architecture in the past. This allows Google to more easily and quickly crawl sites.
Bing acknowledges this too. Rick DeJarnette of Bing Webmaster Center recently said, “You can have great content and a plethora of high quality inbound links from authority sites, but if your site’s structure is flawed or broken, then it will still not achieve the optimal page rank you desire from search engines.”
If Google begins incorporating the breadcrumbs display as in the above tests, on a mainstream level, that will be all the more reason to clean your site architecture up, at least in the navigation area. Site architecture certainly goes beyond this, but it is a key part of usability anyway.