Google : Blog Search : Universal Search

Blog Search Engine:

Like the www search for searching pages on the net, Google’s blog Search indexes blogs by their site feeds, which checking frequently updated data (specially on blogs). New and unique content is always preferred by this engine while frequency in update will make you more visible than standard web searches. Data in a structured form such as site feeds help in publishing and sharing the data across the web much faster.
http://blogsearch.google.com/

Google Universal Search Engine :

Google universal search engine combines the advantages of online search box search and the desktop search to find unstructured information in the form of documents, presentations, and emails, or structured business data in ERP and CRM applications.
http://www.google.com/enterprise/universal_search.html