Like huh? Unlike the Wi-Fi Detector and Dynamic Life T-shirts, which could be considered moderately useful, the Interactive Portal Shirt from ThinkGeek simply doesn't seem viable. Mounted in front of the apparel is a wireless 5.8GHz pinhole camera and TFT (thin film transistor) LCD display. The shooter projects what you see to the person wearing the other shirt by displaying it on the wearer's screen and vice versa, creating an imaginary portal between the two people.
It's completely useless if you buy only one shirt since the "portal" requires a pair to work. Two shirts, by the way, will empty $200 from your wallet.
(Source: Crave Asia)