Ridgerunner here, Im going to have to agree with Dave. I have broken too many wire saws to count, and the pocket chain saw is just too damned heavy to fit in your pocket. However, a decent little saw can be had for five or six dollars at most sporting goods stores called the Sierra Saw. It folds and locks like a lockback knife and will do most tasks a "pocket" saw needs to do. Above that, a decent folding camp saw such as the Sven Saw or the Gerber foling saw makes a great addition to your BOB and camping pack. A decent folding saw can be found at just about any hardware store and are lightweight and functional tools. These gimmick saws are just not a good idea.
Whatever you do, don't buy the Ozark Trail folding saw. It breaks very easily.