Google search offers some nice ways to show of their popular searches in realtime. Here are two examples:

And a widget to show of the most popular searches on Google in your country.

A full screen representation of the most popular Google searches is also available from Google. You can use this for example on a flatscreen monitor to show. See this page.

For devs you can use this url to get the search trends from 17 different countries: https://hawttrends.appspot.com/api/terms/.