Knowledge NewsThis is a handy and somewhat interesting website that allows you to sign up for a Knowledge News newsletter. Although this service is not free, you can sign up for a trial run which basically shows you what you can expect to get. After the trials runs out you have to pay to continue to receive this service, however I have received extra ones every now and then.
Basically, every day you get sent an email that focusses on one topic and contains all sorts of information about that topic. While I was receiving it I found that usually the newsletters I was sent were about or regarding things that were happening in the world. For example, when that whole Israel thing was going on, I got an email all about the history and conflict in Israel.
This is deffinately worth a look, even if you don't decide to continue the service.