Google Analytics added a new option for charts: graph data by hour, day, week or month. The hour graphs are only available in some of the visitors reports and they could be helpful to find out the time of the day when most people visit your sites. The graph below shows a strange shift that happened in the past year, even if the regional distribution of this blog's visitors hasn't changed too much.
It would be nice to see aggregated graph for days of the week, for months and for years, enhanced with some possible explanations for the changes, like we can see in Google Trends and Google Finance.