Google has announced the launch of it’s new Search-based Keyword Tool which will give you a better idea of what your potential customers are searching for and which keywords you should use. The most interesting thing about this tool is that it finds those relevant keywords which are currently not in your AdWords campaign (if you are running adWords). Based on your URLs, the Search-based Keyword Tool displays a list of relevant user queries that have occurred on Google. you can try this tool here: http://www.google.com/sktool