How to get 99 lives. (3 separate ways)
1st way: Go to world 1-4. Go normally until you reach the Red Koopa just before the big wall with all the brick blocks in it. Jump on him ONCE. Then press the Dash button (either X or Y) to grab the shell. Hold dash to hold it, then run for the area between the two pipes, one of them spouting Goombas. Get in the centre and throw the shell. Jump OVER it when it comes back at you. If done correctly, you'll get 99 lives easily.
2nd way: Go to world 7-5. Get a shell, as before. Chuck it between the two rotating Bullet Bill Blasters shooting at each other, and et voila! You'll have 99 lives in no time at all*!
3rd way: Play 1-1 until you get to where the Mega Mushroom is. Go ahead for a minute and stomp the Goomba. Then go back and hit the Mega Mushroom Block. Wait until it's almost over the cliff on the right side, then collect it. Go in a straight line, and don't jump over what you can break through. If you're not a moron, you can smash through the end flag (I personally like to jump on it, but whatever you like) and collect five lives. Repeat as needed.
*Note: This trick will take very long, if it works at all**.
**Note note: The trick pertaining to the Bullet Bills may not work at all, although I think it will. Also, this trick does not work with a Blue Shell.
Added by: Guest Dec 9th 2010, ID#14939