last week I run into interesting site about digital room correction (DRC) - http://www.duffroomcorrection.com/wiki/Main_Page
... and I think this could help my little room :)
I installed BruteFIR (convolution program) and ported it to MacOS X. Jack OS X is also a nice to have.
DRC-FIR (http://drc-fir.sourceforge.net/) is also a nice package, but I found FuzzMeasure much better (http://www.supermegaultragroovy.com/products/FuzzMeasure/).
Anywat you need a measurement microphone to record a room impulse response. The key point here is to have it calibrated, but those mics are really expensive... therefore I made myself one :D
It is based on WM-61 capsule (with Linkwitz mood) running on 9V battery. I haven't done a microphone microphone, since I have an external "sound card" with a very good microphone amplifier.
It works nicely, except it is not calibrated - still need to know how to calibrate it (at least approximation of it).