Goku used to have a magical flying cloud (Kinto'un) and an extending staff (Nyoibou). Later on in the series (I think at DB-Z second half, but I am not sure), they were not shown on-screen anymore.
Considering the whole Dragon Ball series (DB-Z, DB-GT, etc)...
What happened to them? Were they destroyed, gifted, lost, stolen, or just hung out to dry?
Regarding the fate of the flying cloud (Kinto'un), according to Flying Nimbus article on Dragon Ball wiki:
During Dragon Ball Z, the Nimbus was used by Goku during the Vegeta Saga. He used the Nimbus to chase down and save Gohan from Raditz, and to race toward the battlefield to save his friends from the Saiyans, Vegeta and Nappa. The Nimbus perhaps most notably saved Gohan from being stomped to death by Nappa. After recovering in the hospital from the injuries he received during the fight with Vegeta, Goku uses the Nimbus once more to travel to the Capsule Corporation and begin his journey to Namek in Dr. Brief's Capsule Corporation spaceship. This is Nimbus' last appearance for quite some time, as most characters learned high-speed flight, which far outclasses the Nimbus' speed.
It is seen again in the Great Saiyaman Saga when Gohan also used it to fly from Mount Paozu to Orange Star High School, and even raced with it after becoming Great Saiyaman. He later gave it to his little brother Goten after getting the Great Saiyaman Watch from Bulma, which allowed him to fly without the fear of someone recognizing him. The Nimbus is only used by Goten once, as he would soon learn to fly after Gohan teaches him. This would be the final time the cloud would appear in Dragon Ball Z. In the 2004 kanzenban edition of the manga, four new pages drawn by Akira Toriyama were added to the final Dragon Ball manga volume. They depict Goku giving his Flying Nimbus to Uub while they are leaving Papaya Island.
As for the extending staff (Nyoibou), according to Power Pole article on Dragon Ball wiki:
When Goku shows up for the 23rd World Martial Arts Tournament, he is also carrying the Power Pole. After the 23rd tournament, Goku uses the pole to fight Annin in the final episode of Dragon Ball. Four years later, Goku uses the Power Pole against Garlic Jr. and his henchmen in the movie Dragon Ball Z: Dead Zone. While Goku was training with King Kai in the Other World after his death fighting Raditz, the Power Pole was shown strung between Korin Tower and Kami's Lookout. Brought by Gohan in Wheelo's fortress, Goku uses the Power Pole again in the battle with Dr. Wheelo in Dragon Ball Z: The World's Strongest. Following this, Goku retires the Power Pole, presumably because he does not have much use for it with his rapidly ascending power.
In the Garlic Jr. Saga, the pole is not between Korin Tower and Kami's Lookout but in Korin's possession, as seen when he bets it in a poker game with Maron and Yajirobe. The Power Pole is later seen extending from Korin Tower to the Lookout several times during the course of Dragon Ball Z, and Goku is seen with it one final time in the Japanese ending credits of "Until We Meet Again", the last episode of Dragon Ball GT.
As seen in the 2 articles, the flying cloud and the extending staff are still there, but no one really uses them. Goku has the extending staff with him in GT, but that is later in the series and he doesn't even use it.
Regarding Kinto Un, Goku gave it to Gohan and, later, had been used by Goten.
Nyoibou was given to Goku by his grandfather Son Gohan. Before, it was used to connect Karin's Tower to Kami's Palace. Goku used it to reach Kami's Palace during his training with Kami, before his fight against Piccolo in the last part of the Dragon Ball serie. It is there until now and can be seen in several DBZ episodes.
Kinto'Un is seen again in Dragon Ball Super when Goku and Krillin enter a forest where they encounter gigantic versions of all the major villains in Dragon Ball Z which grow as they use energy, so Goku calls on Kinto'Un so he can get a view from above without spending energy to fly.
