Searchweaver is a multi search engine that breaks knowledge down into several major categories, such as search engines, health, internet marketing, news, reference and so on. Within each category it pulls on data from various different engines as appropriate. Choose those that interest you and then run your search. Searchweaver then brings back the data essentially in a frame, and you click on each engine in turn to see what results they return.
Maybe it's just me, but this type of engine is getting really old and tiresome. Trovando has this down and sorted and if you want this approach, then that's where you go. I have no clue as to why I'd want to use Searchweaver, and more importantly, they're not telling me.