My favourite was this http://www.bikeradar.com/forums/viewtopic.php?f=40044&t=12879937, where some bloke assumed another identity so that he could agree with himself, and then got mixed up about which ID he was posting from and ended up talking to himself. He got outed and banned...hilarious!
Oh, man the mumsnet was good fun.
Yossina, Doook and candida McThrush are dead, long may they live.
Mumsnet have banned me on my IP address so i can never go back...........