This is a simple clientside script that mimics the way NPC's look around, but for players.
You can use this as is (automatically loaded by the client from lua/autorun/client), or you can include it in your own projects by putting this in a shared file (assuming player_look.lua is in the same directory):
AddCSLuaFile "player_look.lua"
include "player_look.luaNote you have to add it to be downloaded by clients from the server with AddCSLuaFile if you're implementing it in your own project.