I ran across it in Layla's journal and signed up on a lark.

It's basically a bloghop, where many blogs touch on the same topics for a period of time, and you can go read other posts in the series. Torn World's first installment is here, on the topic of Geography and Climate:
http://torn-world.livejournal.com/134270.htmlThe second installment is History and Politics, and is posted here:
http://torn-world.livejournal.com/134506.htmlTomorrow's installment is on Magic and Religion, though I will be concentrating on time crystals, Others and boundaries.
Day four is Food, Drink, Holidays, & Culture, and Day five will be an excerpt with an example of the worldbuilding.