Hoople - 9:16 pm on Jul 17, 2010 (gmt 0)
It has been mentioned here that the format of addresses has some significance also.
123 Main Street
123 Main ST
123 Main St.
To humans they appear equivalent. Not to Google it's been said. The US Post office and those following their lead prefer the bolded version. Going to the data sources and making them uniform helps unify the data sources secondary content (reviews, comments, pictures, etc) on Google maps too.