Vivisimo launches Clusty, an expanded and enhanced version of their clustering search engine that includes web, news, image, shopping, blog, and other types of search.
The quality of the clustering seems quite high. I found a shopping search for "turtle beach" created appropriate clusters for sound cards and even subclusters for 5.1 and 7.1 cards. A vanity search does a fairly good job of separating my work out from others with the same name and clustering various parts of my career. Although the coverage and quality of the default search results seems lower than Google to me, the clustering makes it easy to refine searches quickly.
Vivisimo's clustering technology was already impressive. This new offering seems quite compelling, a strong alternative to Google.
Chris Sherman and Gary Price have an excellent write-up on Clusty and its features over at Search Engine Watch. The New York Times has an article with a good high level summary. Steve Rubel points out that Clusty includes a blog search; it's disabled by default, but you can turn it on at the customize page.