Thanks Mad_Mat for clearing those portage trails.  Since we usually go in the late summer, it's rarely a problem for us.  We usually bring a Leatherman or Gerber Multi-pliers per person plus 1 fillet knife per canoe.  I also keep a one-handed, quick-opening, locking folder on me on trail and most always back in civilization (airports and gov't buildings don't like 'em) for all of those little tasks that seem to come up when you already have your hands full.  It serves similar purpose to the fixed blades suggested, but is a little more discrete.  Personal preference is a Spyderco Endura or Military model