imdb.com), based on his homonymous autobiographic novel, lets us share Thomson´s experiences while he was working for a newspaper in Puerto Rico in the 60s.
The film displays the boozed & stoned spirit of the writer`s alleged tropical adventures and looks partly like an hallucinatory trip. Bruce Robinson, the director of the flick, had a bottle of alcohol a day while writing the script, explains Wikipedia (wikipedia); the screwyness of the movie also reflects the high temperatures (above 100 Fahrenheit) and the extreme humidity on the set.
I reckon Johnny Depp is perfectly cast as the young, boozed and curious Thompson (named Paul Kemp in the film). Depp`s face acts as a screen for the surprises, misbeliefs and disgusts the writer experienced on his exotic travails. Giovanni Ribisi, who acts as the perma-drunk and stoned workmate, fits well into this intoxicated climate. The alluring Amber Heard, who plays Kemp/Thompson`s object of desire, legitimates her casting as well. She seems to be more disturbing and addictive than all the rum and drugs together. I had fun with Thompson`s exotic & boozed adventures and left the cinema without any hangover.