Based on my experience, when it comes to these types of devices you will definitely get what you pay for. WiFi detectors come in various forms and prices. The cheapest models will run as cheap as $10 but will most likely provide sparse details on what it's actually detecting. For example, it will probably tell you that there is a wireless network somewhere and what the signal strength is. Don't expect these devices to tell you what the name of the network is or whether it's secured or open to the public.
Over the years, I have received a handful of these cheap WiFi detectors from conventions as promotional give-aways and as hasty birthday gifts. Most of them sit in a drawer because they were utterly useless.
It wasn't until I found the HS20 Digital Hotspotter from Canary Wireless (http://canarywireless.com/) that I felt that I owned a truly useful WiFi signal detector.
What makes the HS20 such a great device? Here's the list of features I grabbed from their site:
- No need to boot-up a laptop to detect whether an accessible Wi-Fi network is near
- Quick glance icons show signal strength and security status for each access point
- Device gives network ID (SSID), allowing identification of public or private networks
- Back-lit display with 96x64 pixels for easy viewing
- Uses inexpensive and easy to find AAA batteries (2)
- Scroll feature allows easy access to multiple access points per scan; highlight an access point name to view details on network type, security open/WEP/WPA, and channel configuration
- Battery meter icon displays status of AAA batteries
- Does not require any additional software or hardware
- Can be used as a network analysis, rollout and maintenance tool
- Uses a true 802.11 engine, resulting in no false readings from Bluetooth® signals, cordless phones, or microwave ovens like some competititors' products
- Slim form-factor easily slips into shirt pocket or computer bag; lanyard hook also allows the HS20 to be attached to other cases
As you can see, the HS20 has a lot of great features but what matters most is that it will tell you the network's name, the signal strenght, and whether it is private or public. That last part is my favorite feature.
Now, the HS20 is a $1o device. It's actually $49.99 + S&H (current MSRP price as of posting) but it's worth every penny.
The HS20 is one of those gadgets that I always take with me whenever I leave the house just in case I have to find a WiFi connection to do some moblogging or quick web site repairs while I'm out. It has proven to be one of the best $50 that I had ever spent.