From StrategyWiki, the free strategy guide and walkthrough wiki

[edit] Menu Controls

PlayStation 2	Wii (horizontal)	Wii (vertical)	Wii (GameCube)	Action
				Make a selection
				Enter selection
				Cancel
				Set rule
				Start race

[edit] Gameplay Controls

PlayStation 2	Wii (horizontal)	Wii (vertical)	Wii (GameCube)	Action
				Steer Character (up and down directions are only required while on foot, boosting, or Air Riding)
				Jump/Trick (on trick ramps)/Grind (on rails)/Slide Turn (hold)(Wheel-type Gear only)/Cancel Boost/Cancel Air Ride
				Gravity Control/Drift
	shake the	shake the	(hold)	Gravity Dive (Boost)/Meteor Burst (if you hit an object while using Gravity Dive, you'll do a Meteor Burst)
				Brake
		or		Gear Change
				Pause Game