Kensington case warns when you leave your iPhone 4 behind

For those of you inclined to leave your smartphone behind after meetings or while traveling, Kensington has come out with a cool new case that alerts you when you're about to part company with one of your most valuable business tools. The catch is that it currently only works with an Apple iPhone 4.

The product, called BungeeAir, comes in two components that work together to tell you if you're in danger of losing your iPhone. It includes a case that you can use to protect the smartphone's body and a wireless BungeeAir Fob that you can stick in your pocket, briefcase or purse. If you walk any more than 50 feet away from your iPhone, an audible alert will sound and the screen is password-locked so that if someone picks it up or snatches it he or she will not be able to see your data. If you're the kind of person who routinely puts things down "somewhere," you can press a button on the fob that triggers an alert on the case so you can figure out where in the vicinity you might have left it. The fob has a battery life of up to six months.

This gadget would have saved my husband and I hours in the early summer when he inadvertently dropped his iPhone under a hydrangea bush he was planting.

There are currently two versions of BungeeAir that Kensington is selling. The first one, which lists for $99.99, adds a battery to the case component so that you have an extra four hours of power for your iPhone. The battery capacity is 1500mAh, and the wireless technology that BungeeAir is 2.4 gigahertz. The second version of the product dispenses with the battery and comes with an adapter that you attach to the iPhone's 30-pin connector, which communicates with the fob. That version of the product is priced at $79.99.

The downside to all this, of course, is if you leave the fob and the iPhone in the same place -- and that place is not with you -- this security doesn't do much good. But if you're absentminded, it probably wouldn't hurt to check out this new product.