I just wrote these two JSPs which I thought others would find useful. One (agentHistory.jsp) shows a list of builds that have run on a specific agent in table format (interim solution for TW-5519). The other (buildStats.jsp) just shows some statistical info for all builds in a given project.
You just need to set your db info in the jsps and drop them somewhere under teamcity/ROOT.
String dbUsername = "SET_ME";
String dbPassword = "SET_ME";
String url = "jdbc:mysql://SET_ME/teamcity";
I hope somebody else finds them useful.