Phew... what a question Andrew.
A lot of us on this BB are scattered around the world, hence its probably better to leave a constructive answer to the USA based members ( particularly JeanneP )
A lot of " hitch hiking" is done over several well known routes, however its a matter of being in the right spot at the right time.. i.e.in the South Pacific ,between May and November.. remember you have to avoid Cyclone seasons etc.
So good luck. You will achieve what you want,just be psitive and select the right opportunity when it presents itself.