From Rainer Langenhan’s newsletter
Keyword map: enter a word in the lower of the two fields (not ‘web search’) to get a map of associations and combinations of the word. The idea is to help you find other combinations to enter into search engines to find what you’re looking for. Doesn’t handle umlauts.
This site represents the relations between search engines.
Nextlinks at Leipzig University allows you to enter a URL and find similar or related URLs. It’s new, and it concentrates on Germany. – Of course, Leipzig University has a lot more available for terminology work.