Hey MeanGene, good to here from you again. You know even doing the bare minimum of treatment for your room can make some pretty cool improvements in your sound. I experimented with just the basic level of room treatment a few years ago in a rental house and got some pretty positive results.
Anyway, There is a lot to cover on this topic and Ethan Winer does a great job at it. Far better than I could ever do. Here is a link to his site with tons of good information on this issue.
http://www.ethanwiner.com/acoustics.html