The Leatherman Skeletool Multi-Tool, at a mere five ounces, it has a stainless steel blade, pliers, bit driver, removable pocket clip and carabiner/bottle opener. This incredibly light (5 oz) tool is perfect for the outdoor enthusiast who likes to travel light. Then again, if you just carry a pocket knife, you miss the additional tools that a traditional personal tool might offer. But, if you carry just a pocket tool, they tend to be heavier and contain more features than you generally need.
The Skeletool is the perfect compromise between the two extremes. With a platform that contains everything you'll ever need, the Skeletool easily clips on to a belt or backpack. It's so light and functional that you won't even need a sheath for it.