"The Shocking Truth About Windows" - link to an excellent series of articles on the Old House Guy website about why character home owners should avoid replacing their original wood windows. A must-read for people living in old houses!
Interior Storm Windows Save Energy and Cut Outside Noise
The Innerglass Compression Window is a vinyl framed, glass interior storm window that mounts on the inside of your primary window using Compression-Fit technology. These storm windows seal tightly, eliminating all drafts, condensation, and outside noise.