Update 2019: All these years later Google Insights for Search is still available and works more or less the same but it is now called Google Trends.
Google Insights for Search is an interesting tool that is fun to play with and could give you some useful nuggets of information that you can use to your advantage. You can use it to see what search terms are most popular and to see how search terms trend over time. For example if you are selling a product on your website and are planning an online marketing campaign, you can see what times of year have the most search activity for keywords related to your product and then time your campaign to occur during a time of peak interest. Your results can be restricted to a specific country or region so for example you can look at the trends across the entire world, or just in New Zealand or even just in Nelson – pretty cool eh?
Google Insights for Search has been around since 2008 but is still in ‘beta’ mode (test mode) – check it out here.