This Journal, known as Perspectives on History, runs through the American Historical Association. It gives great perspective on various aspects of history through how its being used in teaching, the media, and through the archives. For any history majors out there, I strongly recommend checking out this journal.
I came across this as I was looking for history of search engines and its pretty crazy that the site Topsy has been able to save every single tweet since twitter launched! that's 300 billion tweets!!! and you can search them all as it is open to the public. I hadn't heard about Topsy but it seems like they are gaining a good reputation and going against big search engines like Yahoo and Bing.
I've added a new avatar for our course Diigo group. It's based on a 1974 map of ARPAnet, the first "network of networks," and thus the precursor of today's Internet. I got it from Wikimedia Commons, which is a great source for all kinds of media that you're allowed to reproduce on the Internet.