My latest gadget arrived today - a Wi-Fi Seeker. It's a key chain sized device for detecting wireless 802.11b and g networks. Just point and push the button, the lights tell you if there is a signal and how strong it is.

It managed to point out the access points in the office and also my internet provider at home (I have wireless broadband as I'm too far from the exchange for ADSL). I reckon it works pretty well.

As for it's usefulness, we'll have to see. But that isn't the point - you have geek toys "just because you can".