Unlock the Secret Characters
     There are 4 hidden characters that can be unlocked:

Drumstick: 
     Fling  a  frog  up to the green sillouette shaped frog picture in
the  world  map  (To the left of Wizpigs face). Stomp on the frog that
comes out.

T.T: 
     Beat  all  of his ghosts in Single Player Race. It DOESNT include
the new unlockable stages.

Taj: 
     Complete Adventure 1.

Wizpig: 
     Complete Adventure 2.

Super Boost
     Before landing on a zipper or using a blue balloon, let go of the
acceleration  button  to get a much stronger longer lasting boost then
normal.

Answers to sand puzzle
     Near  the  lighthouse,  theres  a  location where you can use the
stylus  to draw puzzles in the sand. If you draw a balloon, you'll get
a  golden  balloon. If you draw a pentagon, you'll get a scratch card.
If  you draw a coin (small circle shape) you can get 10 coins, but you
can do this up to four times.

Unfreeze the balloon
     In  the ice area of the overworld map theres a balloon stuck in a
block  of  ice. Using the DS's touch screen pad, you can slide it down
into  the  water  to unfreeze it, then follow it down the river to the
beach where it melted to collect it.

Coconut tree coins
     Some  trees  allow  you  to  launch coconuts using the DS's touch
screen.  If you launch them at the wall they will create cracks in the
wall, and for a short period of time coins will pop out of them.