Glass block walls are a great design feature that let extra sunlight into any room in your home while still providing a certain amount of privacy. The individual blocks have a coating that's designed to bond with the mortar, which helps keep the wall waterproof. Be sure to hire a professional to do the job.
For more on glass blocks, consider:
Walking on Glass
Glass Block Floor System Installation (VIDEO)
10 Trendy Ways to Use Glass Block in Your Home Design