Dragonball Junk
Gravity Room: One of Dr. Briefs inventions. It was used in a capsule corp. spaceship to change the gravity in the ship. Goku used this on the way to Planet Namek to train. Vegeta also used it on Earth to prepare himself for the arrival of the androids.

Capsule: You have probably seen it in the series; they're small, light, capsules, but inside those capsules are cars or spaceships or whatever!On top of the capsule is a button. Push the button throw the capsule away and...Tada! A complete car(or whatever)Another one of Dr. Briefs inventions.

Supersaiyan
Goku: Goku was the first saiyan(one that could control it's power)that turned into a supersaiyan. This happend at Planet Namek, right after Freeza killed his best friend Krillin. Because of this he turned into a supersaiyan.

Vegeta: Vegeta went supraiyan for the first time in Space. He trained intensively on Earth and goes into space and trained some more. Vegeta gets badly hurt and realizes he no longer cares about getting stronger then Goku. That's how he got supersaiyan.

Mirai Trunks: When Android 17&18 kill his best friend and mentor Gohan he got very angry and changed into a supersaiyan.

Trunks: When Trunks turns into a supersaiyan isn't really known. I think he is about seven or eight. He gets supersaiyan while training with his father Vegeta.

Goten: Goten turns supersaiyan about the same age Trunks did. He went supersaiyan when he was fighting Trunks in a tournament.

Gohan: Gohan turns into a supersaiyan while training in the hyperbolic time chamber.