Many smaller Leatherman tools have a key ring, so you can attach it to keys or a key ring.
The Leatherman key ring is a typical split ring that requires something sharp to pry open a bit, so you can slide it over a key or keychain. You can also simply remove the ring if you don't want it catching on your pocket material.
Many Leatherman tools have a fold-out lanyard ring that serves the same function
.Most Victorinox Swiss Army knives have a key ring.
Many Wenger Swiss Army knives also have a key ring.