Richard posted a link to Active History. It's an English site and costs about $80 for annual membership, but it's good value if only for the huge variety of activities for year 12 Modern History students(alas, no Ancient History!) and a bit of historiography for Exrension History. There is a lot of free stuff to whet your appetite. Games such as Fling the Teacher are great for some fun revision.
This whole site is kind of interesting in what they are aiming to achieve. Might give you some food for thought in how you could create a similar situation in your class
Welcome to HistoryBuff.com, a nonprofit organization devoted to providing FREE primary source material for students, teachers, and historybuffs. This site focuses primarily on HOW news of major, and not so major, events in American history were reported in newspapers of the time. In addition, there is information about the technology used to produce newspapers over the past 400 years. Our latest addition is panoramas of historic sites in America.