The can opener on mid-sized and large Wenger Swiss Army knives includes a sharp, effective can opener. This blade is designed specifically for opening cans (unlike the Victorinox can opener, which also has a screwdriver tip).
Uses: The Wenger can opener is not the world's fastest can opener, but it does a decent job for occasional use. The trick is to puncture the can with the sharp part of the blade, and then pull it forward by about 1/4" (6 mm) and slice a bit more of the can with the sharp edge. It works best if you move counter-clockwise around the can.
WARNING: The can opener may leave a jagged edge on the can, so use caution!