room analysis software

There is a free program called REW on the Home Theater Shack website. All you need to do is be a member and you can download the program. There is plenty of help and useful links to help get you started as there is a learning curve to use the program. I use my Mac, radio shack spl meter and a couple cables for the program.

I've also been playing with room treatment and using the program to help see where the problems are.

Here's a link: http://www.hometheatershack.com/forums/rew-forum/

I'll second that. REW works very well on a Mac.

You need to be patient when setting up Rew tho.

These are the low/reasonably priced options, imho:
RoomEQ Wizard (must add mic and preamp)
R&D (must add mic and preamp)
XTZ (complete hardware/software package)
Omnimic(complete hardware/software package)

Kal

Try the RTA Lite app for your iPhone.