Leatherman PST, 'cept my current one has the serrated version of the blade
Half the size of a regular multitool; light and small enough for a pocket, big enough to work as a tool.
No longer made, not even since they moved to China, I'm always on the lookout for this old American version in pawn shops and gun shows.
Also got a little Leatherman Micra on my school key chain.
Birdwatcher