At the start of the game :: Ruby, Sapphire & Emerald Story

At the start of Pokémon Ruby and Sapphire, you get a cool mystical starting screen.

When you start, it looks like you're outside your house in Mishiro Town, where there is a truck parked outside. First of all, its quite shocking that there is a vehicle in the Pokémon world, and secondly, there 'aint no Mew under that truck.

Somehow, the storyline will involve the new Professor, Odamaki getting attacked by a Pochena or something. Your job will be to find his bag. You can see it on the screen above. Once you find the bag, it looks as if you'll be given a choice to which starting Pokémon you pick, as illustrated by the lovely picture below. You'll probably then be greeted by the Professor in his lab. Of course, these events might happen in a different order.

One final note regarding something that doesn't happen at the beginning of the game, but does involve you: You will have a "secret base" in a cave somewhere that you can decorate. It will probably be like your room in GSC. The cave is created by Pokémon attacks in a "small hollow" in a field. With only your game, you can only enter your base, but if you and a friend link up using the PC's "trade corner", your friends secret base is added to the field. Sounds amazing.