I just found this feature on google search which is called ‘Google Suggest’. As you are typing your keyword, there will be more suggested keywords available in drop down menu. Further more, it will show you total number of results for each and every keyword.
I think it will be quite useful for internet marketers out there to get more specific keywords and supply for the keywords.
Here is the screenshot of google suggest
Go to search with Google Suggest
or install Google Suggest as Firefox Extension