One approach to finding Wi-Fi hotspots is to use a Wi-Fi Finder, a small, inexpensive device that has appeared on the market recently.
The most commonly used Wi-Fi Finder is the one from Kensington Technology Group, model number 33063. This tiny unit measures 2.7 by 3 inches, and is about a 1/2-inch thick.
It's simple to use the Wi-Fi Finder. When you're out wandering, press the unit's button. If it detects an 802.11b or 802.11g Wi-Fi network, the green lights light up. The more green lights, the stronger the signal. If only the red light appears, there's no Wi-Fi network in the neighborhood.
The Wi-Fi Finder blocks out competing 2.4GHz signals from devices such as cordless phones and microwaves, so that when it shows a signal, you know it is from a Wi-Fi network. It has an effective range of about 200 feet out of doors.
So far, so good. But the fact of the matter is that you can't tell from the Wi-Fi Finder what the SSID of the network is, who the network provider is, whether the hotspot is free or commercial, whether the network is open or closed, and if closed, who to contact for access.
So a Wi-Fi Finder is a fun and pretty cool thing to put on your keychain (the Kensington model comes with a ring for attachment to a key chain). But is it genuinely useful? That probably depends on the user, but you can definitely find me out cruising the neighborhood to see where the Wi-Fi is using my handy-dandy Wi-Fi Finder (see Figure 11.11).