Hakoda's Boomerang was bestowed to Sokka, a primary role in Avatar: The Last Airbender, from his father, Hakoda before Hakoda departed Sokka and his sister, Katara, to fight in the war. Because Sokka was left as the man of the house, being with his younger sister and grandmother, he sees his boomerang as an attachment of himself and the main protection he can provide for his family.
During his journey with The Avatar Sokka's Boomerang proves to be worthy and effective, saving lives on numerous occassions. One of the more commonly known instances was when Combustion Man was sent to take out Aang and friends and none of them were close enough to hit him. Using his wit, Sokka angled the boomerang to take Combustion Man out.
In the last episode, Sozen's Comet, Sokka loses the boomerang when saving Toph's life. Though it is unknown whether or not he was able to retrieve it again, Sokka was portrayed to be very happy despite his loss - he was able to save the life of a dear friend, and for that his boomerang served its purpose.