Australia Facts tweets two facts about Australia every day, upside down, to @AustraliaFacts_. Sometimes the fact is rendered as an image, in which case it is posted to Tumblr at australiafacts.tumblr.com, too. (Twitteroauth is required to post to Twitter; Tumblr posting is built into the script.)
Australia Facts runs from a Google Spreadsheet using Google AppScript, which makes it easy to compile facts collaboratively. When a fact is randomly selected by the script, it is marked as "used" so it is not selected again. When only a few facts remain, an email is sent to alert the project owner.
The script expects a spreadsheet constructed as below:
Images are created with ImageMagick using pre-selected background images. A fact has a 1-in-6 chance of becoming an image, unless it contains a 2 or a 7, in which case it always becomes an image. (We were unsatisfied with the options for upside down 2s and 7s.)
A cron job randomly runs the scripts twice a day inside a given timeframe.
#between 11am and 12pm
0 11 * * * perl -le 'sleep rand 3600' && php /DIRECTORY/TO/australiafacts.php
#between 5pm and 7pm
0 17 * * * perl -le 'sleep rand 7200' && php /DIRECTORY/TO/australiafacts.php
Australia Facts was made by Jason Eppink and Larissa Hayden.