Many years ago in South Molton street W1, (It was featured on the last Ab Fab when the girls went shopping) opposite where I used to work; a bloke parked a very rusty old bike on the kerb and went into the jewellers. After a couple of minutes a very shiny roller came along and parked in the same place, knocking over the bike. The driver looked down at the bike and went into the jewellers without righting it. The first bloke came out a few minutes later, looked at his bike, looked at the roller and then picked up his bike and slammed it down on the bonnet, picked it off and rode away. Very funny.