pzztgotbagz: good idea but I'm far to busy to be able to start up anything like that! plus I agree with Wideawake: not sure about the market size. BUT, I could see you doing a small project like that for either people on this board or other 6700 boards.
As Wideawake said: eGrips. get them
HERE
You could also zip down to RadioShack. They usually carry the generic eGrips (they're not specifically cut for the 6700). You can get those in black. I do highly recommend them though. great for preventing the phone from sliding around.
As far as is really Louder? Definitely yes. It really cranks now.