Just come across this great little article entitled 'Why Round Sunglasses? A Style Investigation' published in The New York Times this week.
WAS it only last year that round sunglasses were considered square?
To see the article in full (and you should!) go to: http://www.nytimes.com/2009/06/11/fashion/11SUNGLASSES.html?_r=2&adxnnl=1&ref=fashion&adxnnlx=1244891919-PJnWp9/e8ZS6UPcYCFINeQ
P.S. I have those Urban Outfitters sunglasses they mention!