On sentinel beach there are two poles, you need
to push them up. So you need to make sure that 
Jak is sitting down (L1) before hitting the pole,
this will push the pole up, so you can get one of
the scout flies.
Submitted by purple at hamster.dk


If u press "o" while doing a double jump, it will
sail you across to give you that extra inch to get
to the cliff.
Submitted by brianmaster at home.com


Get 100 or more power cells and finish the game to
see a secret ending. If you get less than 100 power
cells, you wont be able to see it.
by unknown


When you go in the deepwater when a big fish come 
just jump and it wil go.
Submitted by muslimkid at hotmail.com