SO I REPORTED A WHILE BACK that a reader who works at Ready Acoustics offered to set me up with some sound treatments for the podcast studio / media room setup. This was a good idea, as it's a fairly big room and a bit echo-y.
The process was pretty involved, with me taking lots of measurements and photos, and them putting those together into a computer model of the room that they used to custom-design the sound treatment. Then they sent me a bunch of absorbent panels of varying thickness -- bass traps and high frequency absorbers -- all covered in a lovely red material (Helen picked the color). Putting them up wasn't too hard -- they mount with screwhooks and plexiglas brackets that mount with drywall anchors. Everything went well, except that the plexiglas brackets were a bit fragile; luckily, they sent a few extras.
The results are excellent. Stepping into the room from the hallway while talking, you immediately notice how much "deader" the room is. It's not totally dead, which would be bad, but there's a noticeable lack of reverberant room tone, and when Helen sat down in front of the microphone she said "My voice sounds like NPR just coming out of my mouth!" It's definitely made a big difference.