This is my first tab, but I'm fairly certain this is accurate, because it's a
beautifully simple song.
So at the beginning and a few times throughout the song, he does these little "dum
dummmm , dum dummmm , dum dummmm , dum dum dum dum" and there is only a slight variation in what
you play. So you play the G, C, D progression for the first bit, then at the last four 
hums he does a quick picking part and this is the tab for that:
E--------------- | 
A--------------- | 
D--------------- | 
G---7---7--5---- | 
B-----5--------- | 
e--------------- | 

Enjoy!

G , C , D picking(tab above) (x2)

G          C
If I had a jet pack,
     D
I'd circle into space,
     G                   C
with roller-blades on my feet
    D
and pencils in my hands.

     G             C
But skating on the moon
    D
is better in the morning,
    G      C
and I feel better when
D
I am drawing

       G              C
So I'll draw myself a picture
   D
a rainbow tailed dinosaur
        G             C
and I'll put him in a bowl
    D
and fill the bowl with milk

G            C
suddenly everything
      D
seems so much calmer
G           C
cats wearing bow ties
D
having tea with a llama

seems great

G , C , D picking(tab above) (x2)

   G               C
and even though I'm running late
   D
to such a rad party
   G            C
I don't seem to mind that
    D
it's already started.

   G            C
My attire isn't fitting
  D
I think there was a theme
  G                        C
I must have misplaced the invitation
     D
that explained everything

     G            C
so I fire up the jet-pack
    D
and head back home
     G               C
but when I arrive to my dismay
D
all my friends have gone

     G            C
oh no I think to myself
     D
I'll draw up some more
    G                 C
but all my pencils are broken
       D
and I left my paper on the moon

what a disaster

G , C , D picking(tab above) (x4)