In pokemon sapphire if you put a pokemon in the daycare, get a machbike, and then go to one of those sandslide things that you can only get up with a mach bike. Once you go there you position yourself one step away from the sandslide. Then you put a lego piece right on top of the up arrow on the d-pad. Then shut the DS, rubberband it shut, and wait for a couple of days. Then you should have a level 100.