The only thing I could find was the typewriter that Sam gives him, but I don't think that's that much of an important symbol.
I recall a lot of tunnelsthat charlie travels through. These are times of darkness that Charlie must contend with. Tunnels are a passage for Charlie. They mean change, reflection, and maturation.
It was me standing up in that tunnel with the wind over my face. Not caring if I saw downtown. Not even thinking about it. Because I was standing in the tunnel. And I was really there. And that was enough to make me feel infinite. Epilogue.
