58 was the order number I was given for the first smoothie I ever ordered in China. When my order came up the guy shouted 'wu shur ba!', 'wu shur ba!' (58 in Chinese). I shouted back 'wu shur ba!' and collected my smoothie. I couldn't stop saying it for a while after that. Everywhere I went I kept saying 'wu shur ba!' Obviously my friends in Shanghai thought I was mental. =8-)
Either that or it was the shortest, easiest to remember available domain name I could come up with as a moniker for my corner of the blogosphere.