ok so someone finally posted a video of them playing petrov yelyena and me live so i 
it over and over again to figure out the chords they play and here they are:

(i dont know the names of the chords though)
A: 577655
B: 779997
C: 557775

For most of the song Bret's strumming is this:
(but in the beginning Bret plucks it like Jemaine's part further down)

    A
e|--5---5-5-5---5---5-5-5----|
B|--5---5-5-5---5---5-5-5----|
G|--6---6-6-6---6---6-6-6----|
D|--7---7-7-7---7---7-7-7----|
A|--7---7-7-7---7---7-7-7----|
E|--5---5-5-5---0---0-0-0----|
(for the first strum Bret just strums the first two strings)
every other strum of this Bret makes the low E an open note

then for the parts like "lost but happy at sea" you strum the B once, then C once, then 
strumming A again:

e|---7---5---5---|
B|---9---7---5---|
G|---9---7---6---|
D|---9---7---7---|
A|---7---5---7---|
E|---7---5---5---|

Then for the parts like "three days later they were hungry again" you play the A chord 
then move down one fret, play once, move down again and play once again, then start the A 
again, like so:

e|--5---4---3---|
B|--5---4---3---|
G|--6---5---4---|
D|--7---6---5---|
A|--7---6---5---|
E|--5---4---3---|

For Jemaine's parts, he does the same thing except he plucks the chords like so:

e|------------------|
B|-----5-5-----5-5--|
G|-----6-6-----6-6--|
D|-----7-7-----7-7--|
A|--7-------7-------|
E|------------------|

then when it goes B, C, then back to A strumming Jemaine just plucks all four of those 
same with when you go down a fret with the A chord

You'll have to listen to it to get where to put the chords strummings into place.

here's the link to the live video of it:
http://youtube.com/watch?v=INg0nP9-1Bs

pretty straightforward song, any problems or changes e-mail me at pizzafreak54@yahoo.com