A continuously updated real-time log of world statistics in a few key and wide-reaching categories (population, government & economics, society & media, health, etc.). Watch all those numbers ticking up automatically; it can be mesmerizing.
Writers can find lots of uses for this information, obviously. While you’re at it, browse through all the data items to get ideas. For example, as of this writing, did you know that 2,173,731 new books have been published this year to date? 1,491 just today so far, in case you were wondering.