Ok, now, this is one of Joe's greatest songs. Personally I love this one, an I am 
surprised this ones not been posted before. Now this is just the main riff of the song, the 
bit that stands out from the rest.

Capo (Or bar chord it) 5th Fret.

And its just simply.

          C         Am      F        C          Am      D

------3-3---3-3-------------------3-3--3--33---------------------|
---------------------------1-1--------------------------22-------|
--------------------------------------------------------22-------|
-------------------2-22----2-2------------------2-22----22-------|
------2-2---2-2----2-22----3-3----2-2--2--22----2-22-------------|
------3-3---3-3-------------------3-3--3--33---------------------|

And just repeat. Listen nto the song to get the right strumming pattern. Its really clear.