The new tool available under the URL
http://www.topicalizer.com/coOccurrences/ tries to guess the words that are most likely to co-occur with the words you entered. That is, if you enter 'president' for example, the software will offer you, amongst others, the word 'kennedy' as possibly occuring in the same context.
This tool draws upon the
Brown Corpus of Present-Day Edited American English.
This new feature is also part of the
Topicalizer API.