Thinkgeek team created a shirt to display Wi-Fi signal, the glowing bars on the front dynamically change as the surrounding Wi-Fi signal strength fluctuates.

It shows signals in 802.11b or 802.11g and it’s 100% cotton. The animated decal is removable (with hook and loop fasteners) for easy washing and the baterry pack is concealed in a small pocket sewn inside the shirt, works for a few hours with 3 AAA batteries.