[Thanks to Ian.]
If you're afraid that the world is not always aware of how big a geek you are, you can wear this tee-shirt which actively displays the strength of nearby wi-fi hot-spots.
I think that in a few years, we can buy clothes like this were the tech and battery is so flat and resistant that it can actually be built into the clothes themselves and not have to be removed for washing.
Admittedly, apart from unsubtle decoration, I don't imagine what good uses this will have. But then there are many good uses and technologies which I did not imagine before they arrived. In fact, that's most of them.