when we i was at school me and a few mates used to do a few. there was a taxi firm the phone number was 654321 we used to ring them and when they answered we used to say sorry what number have i rang and when they said 654321 we used to all shout blast off, thinking about it know its not even funny but we used to piss out self and she used to get proper mad.
an other one that we used to do was ring random numbers and ask to speak to mr wall and they would say he dose not live hear so we would say mrs wall they would say no so we say any walls in the house they say no we say well whats holdin