search engines

• Google Trends: Allows you to tap into Google's database of searches, to determine which keywords are most popular. View the volume of queries over time, by city, regions, languages and so on. Compare multiple terms, as well. Offers a list of what is trending now in Hot Searches.
• Google Insights for Search Beta: Shows search volume patterns since 2004 by geographic, time frames, categories, and in Google properties such as image or product search. The category feature can be powerful for marketers because it offers insight into how searches are put into popular category classifications.
• Google Autocomplete: Google's Autocomplete is a tool that can help 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 works to predict search queries in real-time based on indexed web pages, personalized search history, other 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.

• Yahoo Clues Beta: Explore trends in search on Yahoo. Top Trends shows most popular search queries by parameters such as time frame, gender, age, location, and category. With the popular queries, you will find news related to the keyword. In the trend analysis tab, you can analyze a specific keyword terms and see demographics related to it.
• 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.
• Bing Webmaster Keyword Research Beta: Find query volumes for phrases and keywords by country and language. This keyword research tool shows data show from organic searches on Bing. It also provides the number of impressions for a time period with Average Bid and Average CPC for ad placements on the top and sides of search results. A comprehensive description of this tool can be found in Bing Keyword Research Tool: Highlights & Limitations.
• AOL Search Trends: Lists the top 50 search trends both hourly and daily on AOL. Data in AOL contains web and image searches (powered by Google), video (powered by Blinkx), News, Shopping, Maps, and Yellow Pages (powered by various providers).

• Twitter Search: Allows you to see what people are talking about on Twitter by keyword, hashtag, or user name. Advanced search has many features, notable is the use of emoticons to find tweets with specific attitude, for example, sad emoticon represents negative attitude.
• YouTube Keyword Tool: Keyword suggestions for terms you enter with monthly search volume on YouTube. As one of the largest search engines, this keyword list will reveal valuable insights as to how people search when they are looking for video media specifically, rather than general search engine queries.
• YouTube Trends: Provides insights into popular videos based on keywords and video views. Trending Topics are algorithmically-generated topics from keywords in the title, tags, and description of the video within sets of videos that are currently rising in popularity. Trending videos are based on embedded video views and views on YouTube.
• Google AdWords Keyword Tool: Enter a term or terms, to see search volume and keyword competition. Advanced options and filters allow you to refine by locations and languages and by desktop or mobile.