New Super Mario Bros. Tips

Quick Replenish of Lives
Basically, If you have under 5 lives and you've just completed a castle level(or anywhere where you get the chance to save) save your game, then go into any level and get yourself killed 4 times or less. 'GAME OVER' should come up for you, so just choose the option continue, then you'll be no further back then you were last time and will have 5 lives(1, 2 3 or 4 more than you originally have if you want to do this)