Plenty of Web sites have guest books, user surveys, or chat areas. Search the Web for sites on a specific topic that may have these features. Anyone can usually browse the information in a guest book or chat archives. If it is an online survey, contact the Webmaster for that site to see if they are willing to share their data. Recognize that any opinion poll conducted on the Net has certain limitations.
Specialized dictionaries identify term usage in specific fields or languages.
Unfortunately, few of us have a complete collection of dictionaries readily available. As such, the Web can be a rich source for finding alternate spellings, alternate uses, and even contextual definitions for new and unusual words. Search an unknown word in one of the Web search engines and the general scope of the results should give some idea of the discipline or even language of the term. AltaVista's language search and international coverage make it especially useful for identifying the language of an unknown term. Enter the term in an AltaVista search and then scan the language designation of the results.