Chords
In drop 
D MajorD tuning (actually he plays it on a baritone guitar):
Intro and verse: "I'm mixing up a bunch of magic stuff"
E--------8/---------------------------------
B--------7/---------------------------------
G------------5--7--9--5--7------------------ etc.
D------------x--x--x--x--x------------------
A------------3--5--7--3--5---5-5------------
D--0-0-------x--x--x--x--x------------------
"I did it" "Do you think..." "Do you think..."
E--------------------- ---------------- ----------------
B--------------------- ---------------- ----------------
G---------9---9------- ---------------- or -6---8---9------
D---------7---7------- ---------------- -x---x---x------
A---------7---7------- -4---6---7------ -4---6---7------
D--7--7---7---7------- -7---7---7------ ----------------
^strum
Or: "I did it..."
E-----------------------------
B-----------------------------
G--------9-----6--8--9--------
D--------7-----7--7--7--------
A--0--0--0-----0--0--0--------
D-----------------------------
"I never did a single thing..."
E-------------------------------
B-------------------------------
G--6----8----6----4-------------
D--4----8----6----4-------------
A--4----6----4----2-------------
D--4-----------------------------
Little jam:
E-----------------------------------------------------
B-----------------------------------------------------
G-----------4--2--------------------------------2-----
D--0--4--2--------2--0--5--4-----0--4--5--4--5--------
A-----------------------------4-----------------------
D-----------------------------------------------------
Other versions of I Did It
Alternative guitar chords and tabs for I did it by Dave Matthews Band
