Since starting to work recently with ECJ, I've posted several messages about 
my experiences on my blog, Invisibe Hand. It is available at

http://dvunkannon.blogspot.com/

My most recent post shows how I've built on the charting support in ECJ to 
create charts with multiple data sets per chart that report different 
statistics about a subpopulation.

Please visit and leave some comments!

Sean - since the work I am blogging about combines several incremental 
changes to ECJ in the areas of a new BitVector problem, reading custom 
parameters, and collecting and charting custom statistics, I was wondering 
if you would like me to write it up in the form of a tutorial? It's about 
the same difficulty as Tutorial 2, just in a slightly different direction.

Cheers,
David vun Kannon