Thinkgeek, the shop of choice for the non-discerning gadget hound, has this amazingly useful (and of course, nerdy) new t shirt.
The Wi-Fi Detector Shirt does just what you'd expect: it displays the signal strength of nearby WiFi: 802.11b and g are supported, and bars on the decal light up, just like a computer-bound signal monitor, but the T won't tell you if the network is locked down or not. And at $30, it's actually cheaper than some dedicated units. Click the picture to see it in action.
Product page [ThinkGeek – currently out of stock]
