Google Correlate is an interesting new experiment on Google Labs which allows you to draw a data series and get back results of search query trends which match your drawn pattern.
As the diagram above shows, you use a pen tool to sketch out an interesting curve shape and then press the Correlate! button to initiate the search. Google then runs rapid correlation tests to discover the best fit patterns of web search activity to return a set of suggested search terms which match this shape. In the example below, the search term “centrino laptop” was the most closely correlated with the drawn shape.
It is essentially Google Trends – where you type in a query and get back a series of its frequency – but in reverse.
On the Google Correlate site you can view a comic which explains the inspiration for this tool as well as a more detailed whitepaper about its development.