Google Trends is a useful tool for tracking the popularity of a search time over time. Google has now revamped the interface to make it easier to filter those results by country, time or type and added a calendar view of topics that have been popular in the last thirty days.
The calendar view is accessed via a small icon at the top right; it supports 13 countries, including Australia.
Previously, those filter options appeared in the left-hand column, but Google has now shifted them to the top of the screen, which makes them more visible.
Google has also added new options to explore its 'Top Charts' listing of popular searches. Right now, that only works with the US version of the site, but Google says "more countries are coming soon".
New ways to explore what's trending on Google [Inside Search]