Here is a trick I found to get around the map quickly in GTA V. Enjoy!
XBOX 360
Invincibility – RIGHT, A, RIGHT, LEFT, RIGHT, RB, RIGHT, LEFT, A, Y
Skyfall (Spawn in the sky) – LB, LT, RB, RT, LEFT, RIGHT, LEFT, RIGHT, LB, LT, RB, RT, LEFT, RIGHT, LEFT, RIGHT
PS3
Invincibility – RIGHT, X, RIGHT, LEFT, RIGHT, R1, RIGHT, LEFT, X, TRIANGLE
Skyfall – L1, L2, R1, R2, LEFT, RIGHT, LEFT, RIGHT, L1, L2, R1, R2, LEFT, RIGHT, LEFT, RIGHT