Blue dot in google maps on iphone 4

Greetings all! I am curious to something. Before I ask the question I will say that I am not talking about the blue dot that shows your current location. What I am referring to is a blue dot that pops up with a zip code and address sometimes. It appears at the top of the screen where the signal bar, time, battery level, etc is located. Sometimes it appears as a zip code and city location but at other times it will be an address. If you go into google maps it will then show a pin on the location. It is driving me crazy because I cannot figure out what it is!

Thanks!