I carry my Leatherman Wave everywhere, and use it most every day. In it's sheath there's two small pockets on the sides, where I put a lighter and a small folding wallet pen. Useful things to have around.
When out in the wilderness I'll also have another plain knife with me.
Either a Morakniv Companion, a sharp, useful, cheap knife. Fixed blade and works great for butchering animals:
Or a carbon steel Opinel, a sharp, useful, cheap knife. Locking folder (open and closed) and works great for cooking: