First, to clear up a misconception about Wi-Fi detectors in general: though they can be used to find and (usually illegally) hop onto someone else's wireless connection, that's not their only use. It's a pet peeve of mine to see technology vilified because it can be put to nefarious or even semi-nefarious use; in the case of hand-held wireless detectors, there are plenty of "non-infringing uses" to which they can be put. Troubleshooting in a house or office is one (wireless base station manufacturers sometimes claim coverage ranges that can charitably be called optimistic -- and even if their numbers represent a legitimate best guess, it seems that no house outside of Stepford is truly typical); making sure that your signal isn't reaching the general public (or is reaching the general public, depending on your inclinations and your ISP's Terms of Service) is another good use; so is finding which coffee shops have both drinks and wireless access. There's also counter-cracker vigilance -- making sure no one has installed a wireless router on your network without your permission.
On several cross-country trips, I've happily used an earlier-generation Wi-Fi finder -- Smart ID's WFS-1 -- to park intelligently at Flying J truckstops all over the United States; though hundreds of Flying J locations are set up as (subscription-based) wireless hotspots, the signal coverage is often haphazard, and it's more economical of time and battery life to spend a few minutes walking around with a hand-sized device than to keep trying new parking spots and consulting the signal meter on a laptop. Even if you have an 802.11-equipped handheld, offloading the task of signal detection (and, if you can, keeping 802.11 off unless there's a connection available) will save your battery a few percentage points.
My first impressions of the device were positive. It arrived in the hated plastic-clamshell packaging, but -- unlike some products -- didn't require a utility knife or dueling pliers to extract. The instructions are blessedly simple, and all fit on the back of the package insert, about the size of a 3x5 index card. (This insert opens up, and I expected to find inside the usual birdseed barrage of legal flummery and useless warnings, right down to "Don't feed this device to babies" -- all nicely absent. Simple product, simple instructions: magic.) The device is a medium grey, with the display located just below the centerline and its lone button in the lower left-hand corner. The required pair of AAA batteries is supplied in the package. (AAAs are nice -- much nicer than fiddly button cells at least; a single AA would be even better, though.)
Canary's device is the third Wi-Fi detector I've tried; Kensington's first-generation key-fob device was the first, but that one has forfeited its place in my toolkit: compared to the others, it is neither as sensitive nor as discriminating in the signals it picks up (neon lights all seem to set it off) and has a less informative display to boot, just three LEDs. (And it seemed the only way I could get all the LEDs to light strongly was to place the thing directly on top of a wireless router.)
Smart ID's four-LED meter may not seem a huge leap up from that, but compared to Kensington's, the WFS-1 is both more sensitive and more directional in its pickup, so those four LEDs actually convey more than a third more information than the Kensington's three. The WFS's more pronounced directionality (even compared to the Canary unit) and simpler display means it still has an important adjunct role for quickly finding the source of a signal.
One thing to note: Canary's take on the Wi-Fi detector, at 4.5 ounces, is the chunkiest one I've seen; it's solid-feeling (read: "surprisingly hefty") and squat -- about twice as thick as Smart ID's, and much fatter than Kensington's. The back is curved, though, making it comfortable to hold, if not to jam in a jeans pocket, and it's only about two inches tall.
To use the Hotspotter, there are only two things you need to know: 1) Hit the little grey button to scan for local wireless networks; if one is located, the screen will display in sequence four pieces of information: the network name, a signal-strength readout (one to four bars), "Secure" or "Open" to indicate whether the signal is encrypted, and the channel number of the detected signal. 2) To scan for more networks, hit the button again. (So it's really more like one and a half things.) The initial scan takes 8-10 seconds; subsequent ones are much faster.
Canary claims the Hotspotter should work up to about 200 feet (with a clear line of site, outdoors); I can confirm that it works to at least nearly that distance with the router in our house, but sight lines and property lines conspire to prevent me from reaching the full 200 feet.
I'm in Seattle's Capital Hill neighborhood at the moment, a target-rich environment if ever one was, and I took the Hotspotter along on a walk to Victrola, a very nice wireless-equipped coffee shop down the street, to see what it said about the neighborhood.
The answer is unsurprising, but something to keep in mind if you'd like your own network to be used only by you: of the 33 unique networks I noted in a 6-block stroll, fully 16 of them were shown as "open" by the Hotspotter. (That doesn't necessarily mean they're wide open, though; see below.) 11 of the networks I encountered displayed common default SSIDs (Linksys, Netgear, Apple Net, and the hot-selling "default"), which with a little googling can yield default admin-interface IP addresses and passwords. While some of the nominally open networks might be employing MAC-based security, I think it would be a conservative bet that well over half of them are simply open to all comers. Is yours?
(There may have been more base stations than the ones I could distinguish, because the coverage clouds overlap so much; I discarded some of the discovered networks as probable duplicates. By walking fast, I may also have missed some in the thickest sections.)
I've come up with only a few niggling objections to the device -- just quirks, really, but they're worth laying out:
First quirk: For some reason, on its initial scan (that is, on being powered up from the Off state), the Canary device usually fails to detect the house network, though scanning again immediately has always found it. This is a trivial point, for one big reason: you'll have to hit the scan button again anyhow to scan for multiple networks.
The second quirk is one I hope is fixed on the Mark II version: the absence of a backlight. Unlike the other contenders in this niche, all of which are based on LED displays, the Hotspotter has a 12-character LCD readout, which is what lets it display so much information in the first place. However, the display is difficult to read in anything but bright light, and useless in actual dark. An internal LED with its own button (or an EL backlight like Timex's Indiglo) would be a great improvement.
Lack of a backlight aside, the scrolling display requires more attention than the one-dimensional LED graphs of the competitors -- a fair trade-off for the additional information to be gleaned. However, it doesn't have to be a trade-off at all: I wish the signal strength aspect of the display was displayed on dedicated LEDs either instead of, or in addition to, the scrolling LCD display.
One more quibble, though it's getting close to looking a gift horse in the mouth: this detector will say whether a particular wireless signal is encrypted, but it can't say whether it's protected by other means. If you use MAC-based authentication, for instance (but not WEP), the signal would still show up as "open." It would be more accurate to label such signals "unencrypted" or "no crypto" rather than "open."
In short, the Hotspotter is my new favorite portable Wi-Fi finder, and handily tops the features of the competition: the WFS-1's stronger directionality and bright LEDs can't beat network identification and encryption status, so Canary's device moves up in line. It works well, is useful for multiple purposes, and provides all the functionality it's reasonable to expect from a $50 device the size of a nice piece of fudge. (And of course the great thing about favorites sometimes is waiting for them to be toppled.)