i have a cheat to make you able to walk forever one after another all u have to do is this, walk around collecting loads of question mark boxes then walk to the park and change you accessory<(to anything),then it should have saved automaticcily if it did push the power buttton on your ds and then go back on, u should then have all the stuff u got froim the last walk u did, plus u are able to go for another walk.so just keep doing that until u get loads of items then all the doubles u get sell them at second hand store to earn some wager.
Nice!