Call graphs yes, but from run-time profile data (Score 1)

Draw some static graphs of functions of interest using CodeViz http://freshmeat.net/projects/codeviz/

Call graphs are nice, but call graphs of large applications done via static code analysis are so huge and dense that become useless. Call graphs taken from run-time profile data, with all those irrelevant nodes pruned out, are IMO much more useful, as they naturally direct you to the most interesting parts, where the action is.