Here is a list of several websites that I have found useful in the classroom.
Math Facts:
http://www.aschool.us/math
http://www.oswego.org/ocsd-web/games/Mathmagician/mathsmulti.html

Spelling:
http://spellingcity.com

Social Studies:
U.S. State Identification Activity
Flash based activity where students match the name of one of the United States with it's location on a map.
U.S. State Location Activity
Drag and drop a state to it's correct location within the U.S. This website also contains many other activities.

Links and reviews to programs that I have found useful.

I finally found the time to update the Moodle Math Question Generator at ASchool.us today. Now it uses less of the Algebra Notation. This should enhance compatibility and reduce the load on the Moodle server. Also if you don't want to mess with the script you can head over to teacherpayteachers and download a set of pre-made moodle questions.

Here is a little bit of Algebra research that I did between students grades and their ability to do their multiplication tables. I've posted results on my aschool blog.