Sphere Factor

Characters using a large, spherical or cylindrical object as transportation and/or a weapon, whether by rolling or bouncing. They may use it by being inside or on top of it.

Sub-Tropes include Floating in A Bubble. Compare Rolling Attack when the characters are the ball.

Examples of Sphere Factor include:

Anime and Manga

Pokémon episode The Flame Pokémon-athon has one of the racers doing this with an Electrode! It ends just about as well as you'd expect.
- One of Meowth's Imagine Spots involve Giovanni using a Donphan in a similar manner.

Comic Books

Batman: at one point the third Robin (Tim Drake) found himself balancing on top of a giant (IIRC) bowling ball. While doing so, he remarked that Batman actually made him practice doing so while in the Batcave.
A infamous Lois Lane story from the Silver Age of comics had her traveling everywhere in a transparent bubble-like vehicle (to protect her from criminals) after she married Superman publicly, making her look like a human goldfish.
Dark Horse Comics's Dark Empire II 4: Battle on Byss gives us, Empatojayos Brand, a Jedi Knight whose cybernetics make him a bit spherical.

Film - Animated

In The Incredibles, Dash and Violet team up to use one of Violet's force fields this way.

Literature

In the Vorkosigan Saga, haut women from the Cetagandan Empire are almost never seen—they float around in opaque force field bubbles (and occasionally get places really fast by jumping off buildings in them).

Live Action TV

Takeshi's Castle

Video Games

Donkey Kong Country: the Kongs can jump on top of rolling steel kegs and use it to plow through enemies.
- Kongs can also ride other Kongs in such a fashion in Donkey Kong Country 3 (Dixie on Kiddy) and Donkey Kong Country Returns (Diddy on Donkey).
Super Mario Galaxy: in places such as the Rolling Gizmo Galaxy, and its sequel, Mario rolls on a sphere with a star in it
Shows up as a level gimmick in Sonic the Hedgehog 4.
- And in Sonic the Hedgehog (2006).
Super Monkey Ball
In Billy Hatcher and the Giant Egg, the gameplay consists mainly of rolling eggs around. However, Billy is on the ground and is pushing the egg around. He derives strength to battle from them, running noticeably faster when he's pushing an egg along and uses eggs as weapons.
There are roller balls in Serious Sam II which you can get into.
Yoshi uses eggs as a means of attack and sometimes turns into an egg as a means of transportation.
The rolling "elevators" from Taejin's Tower in Final Fantasy XIII. They get around by rolling, but they only roll two-dimensionally (up/down or forward/backwards).
In Mario Party 7, there is a mini-game where players are split into teams of two and have to cooperate in navigating a gigantic ball, via pushing it, through an obstacle course.
Kingdom Hearts: Birth By Sleep: Ven can use yarnballs this way in The Castle of Dreams.
- The link attacks of the Hornceratops and Drill Rhino dream eaters in Kingdom Hearts 3D have them transform into a spiky ball that Sora rides in this fashion.
The Legend of Zelda: Skyward Sword
In order to create the stars, planets and constellations in Katamari Damacy, the player must roll a Katamari and gather materials from their surroundings. Anything can be used as materials for Katamari.

Western Animation

Done several times on Scooby Doo.
The Jimmy Neutron movie has Jimmy bouncing around to school in a spherical bubble. It pops, much to the amusement of his peers on the bus to whom he had just been condescending.
Phineas and Ferb do this on a giant gumball machine in Are You My Mummy?.
- They also have done bowling from the inside of a giant bowling ball. And a giant bubble. They do a lot of spherical travel.

Real Life

Zorbing.