You may've most likely noticed Sitelinks, the set of links below some search results that lets you jump directly to useful pages deeper in the site. They've been so popular that Google has decided to give more:
Google, Search, Web Search, Internet Search, Search Result, Sitelinks, New Features
From Google blog: …our algorithms have been working overtime and we've recently started showing up to eight Sitelinks per site instead of just four. These extra links let you quickly access even more areas of the top site, and all eight sitelinks together give a good overview of a site's content.
We've also been tweaking things here and there so that Sitelinks will appear for many more websites, and with more descriptive names.