This stuff is really cool. While packing my stuff, I like to turn on the TV. I usually turn it to HGTV to get some decorating ideas for my new place in Colorado. They are showing some new hi-tech home solutions, and they showed soundproof drywall. It's a drywall with a polymer coating to reduce DB's and keep sound either in or out. They gave an example by showing a ride cymbal coated with the polymer, and oen without the polymer coating. The one without rang out like normal, but the one with just sounded like a muted pie pan.
This stuff would be great in a home studio! Not only would it help reduce the sound from your control room and other live rooms, but it would help keep the sound away from the rest of your house and away from the neighbors!
Here in Bloomington, I live in a house next to a bunch of party-loving college students. My walls are paper thin. I REALLY wish I had this stuff on the walls in the house I'm renting!
Here's a link to one manufacturer of this soundproof drywall!
Of course, there's much more to soundproofing than just putting up soundproof drywall, but it certainly can't hurt! Here's a link to an article with tips for soundproofing.