Given the fascination that gadget makers have always had with the pen, something like this Wi-Fi detector was probably inevitable. After all, we've certainly seen stranger combo writing instruments, including everything from cameras and DVRs to SD card readers and, our personal favorite, aromatherapy.
The latest is a natural progression from the "Auto Detective Pen," which warns when you're in the vicinity of a wireless signal that could be used to operate a spy cam or other surveillance equipment. (Chinavasion makes both devices, but at least the hot-spot-finding version isn't based solely on paranoia.)
Using two button cell batteries, the pen has four LED lights that indicate the strength of Wi-Fi signals up to 30 meters away, according to 7Gadgets. And you can even use the pen itself to write down the best locations. How analog.