I remain deeply skeptical, if not outright opposed to the whole "value-add" method of teacher evaluation. As I've argued before, if we get too caught up in tracking test scores, we will miss out on a lot of other things we need to look at to assess teaching and learning.
That being said, there is an incredible wealth of data -- numbers of all sorts -- to look through.
- EDMoney.org tracks spending of ARRA funds in states, school districts and schools.
- ED Data Express is the Department of Education's project, and the site include demographic, budget and assessment data.
After looking at how Pete Warden mapped the data from the LA Times article using his OpenHeatMap tool, I bet there are some more interesting visualizations and analyses to be had here.