PCTel will distribute a keychain-sized Wi-Fi signal detector designed by Chrysalis Development: Despite the enthusiasm in the press release, and the coolness factor of the size and nature of the device, many questions are left unanswered. PCTel says they will distribute this device, but not at what cost or on what basis. There's a lot of focus in the press release on the intellectual property rights associated with it, but that has more to do with protecting the design than how customers might use it.
A Wi-Fi signal locator is only useful in limited circumstances. If you're in an area in which you wonder whether there's a signal, a sensor that can inform you in the affirmative or negative obviates you having to remove your laptop from its case, power it up, and run a sniffer.
But even though this device claims to distinguish 802.11b/g networks from general 2.4 gigahertz microwave signals with directionality, it doesn't identify individual networks. If you're in Manhattan and you want to know whether you can connect to a given hotspot network, this doesn't help. You'll always see a strong signal indicator in any urban environment.
Since the introduction of Kensington's difficult-to-use but sophisticated WiFi Finder, which actually has a built-in 802.11g chipset, I've been waiting for a small form factor device that would actually display a scrolling list of discovered networks -- a mini-stumbler that's entirely computer-less.
Even better, a micro-form factor unit with a USB interface so that its firmware can be updated. Kensington revised the firmware of its WiFi Finder, but there's no way to update older devices. It could also store limited information about which network names are associated with which WISP networks so you could specify to sound an alert when a Boingo hotspot was found.
The ultimate device would have a series of LEDs that would provide true directionality advice--"cold, cold, warmer, HOT HOT HOT"--so you could actually hone in.
It's still unclear whether handheld Wi-Fi finders are more than a novelty if they only have directional signal strength displays.