Vivisimo for research. It sorts the results into clustered sections based on the types of pages returned. For example, a search for porn returns:
porn (107)
Free Porn (16)
Hardcore, Sex (14)
Search (9)
Spam (5)
Pictures Movies (4)
Frontline, American Porn (3)
Free adult (3)
Addiction (3)
Etc...
Try it
Vivisimo