For a while, we've been wondering what the different colors for the map pins represent. We have seen red, blue, purple, brown and other colors over the years.
Mike Blumenthal heard back from Google on what the blue pins represent, he posted on Twitter that Google told him "blue dots represent that which you searched near." The example for this is a search on [restaurants near empire state building]:
You can see, the blue dot here is the Empire State Building, with red dots representing the restaurants and I see some brown dots, orange ones and more.
But at least we know that the blue dots should represent what you searched nearby for.
Forum discussion at Twitter.