Hi,
Hopefully these sites might be of help to answering your question...

# Google Trends: Allows you to tap into Google's database of searches, to determine what's popular. View the volume of queries over time, by city, regions, languages and so on. Compare multiple terms, as well. See our review: Google Trends: Peer Into Google's Database Of Searches.
See URL >> google.com/trends

# Google Zeitgeist: What people are searching for at Google and its associated specialty services in a variety of categories. There are versions for various countries, as well.
See URL >> google.com/press/zeitgeist.html

# Google AdWords Keyword Tool: Enter a term or terms, the use the drop-down box to see the popularity of terms and popularity over time.
See URL >> adwords.google.com/select/KeywordToolExternal