Traffic in Samoa drives on the left. Samoa changed from driving on the right-hand side of the road in 2009. Since then there has been an avalanche of cheap, reconditioned cars from Japan and traffic jams, previously unknown, are now common in the capital, Apia. Even on the roads outside the capital traffic tends to move slowly, due to the cautious and inexperienced drivers and to the numerous speed bumps.
Generally your best bet. They are cheap and plentiful. The Samoa Tourism Authority (http://www.samoa.travel/), to be found in front of the Government office complex on Beach Road, Apia, has a price list for Apia. Do agree on a price ahead of time; if they think you look rich they may try to overcharge you. You can get one for a whole day for about the same price as a rental car.