Smart Target's Kiddo Kidkeeper Proximity alarm helps bring peace of mind to the parents of adventurous children using a wearable wireless transmitter. When a child has wandered out of a pre-set range, the transmitter will trigger a visual and audible alarm on the parent's receiver, prompting them to reel the kid back in.
The device offers two range settings of 13 and 26 feet, it is waterproof, and it can monitor up to four kids at once—which is great until a hyperactive child decides to remove the device and hurl it into the woods for no good reason. There is no pricing information on the official site, but we did come across a Romanian site selling it for the equivalent of $170, which should be a decent indicator. [Kiddo via Gizmag via OhGizmo and Store4Kids]