• Google Trends: Allows you to tap into Google's database of searches, to determine which keywords are most popular. View the volume of search queries over time (since 2004) worldwide or by regions and subregions, by languages, categories, and in Google properties such as news, image, or product search. Compare multiple terms, as well. ***Offers a list of what is trending now in Hot Searches.
• Google Autocomplete: Google's Autocomplete is a tool that helps to round out your research by providing keywords as seen through the searchers’ experience. When a searcher begins to type into the search box on Google.com, additional keywords are offered for searches that could be similar to what is typed. Google's algorithm predicts search queries in real-time based on indexed web pages, personalized search history, users' search activity, and Google+ (for person's name). Since the results are personalized, you may wish for more control over the Autocomplete feature. This can be accomplished by logging out of Google, turning off customizations, deleting web history, and Google+ settings.
• Yahoo Buzz Log: Shows top overall keyword searches by Yahoo users with rank, buzz score, and how the search volume has moved in rank. There are additional options to narrow the buzz log by categories such as actors, movies, music, etc.
• Bing Trends: More of a report, the Bing Community Search Blog breaks down billions of search queries from the previous year and offers insights by popular interests.