Are you paranoid about people leaching off of your wireless internet, and of the aliens reading your thoughts from outer-space? US-based EM-SEC Technologies has tested a new product that might be able to help you out. Well, they might help you protect your wireless internet, you're going to need something more to keep the aliens out of your head.
They claim that this RF-proof paint will block wireless signals (likely including cell phone signals) from being transmitted through the walls, while still allowing the signals to function within the painted area.
This might not be the wisest of products to use within your house if you want to still receive phone calls. However, corporate conference rooms, movie theaters and other such places will likely benefit greatly from this paint.
US company offers Wi-Fi-proof paint [via theregister]