The announced time of the summer solstice is 0545 GMT on the 21st of June 2009.
Depending on your time zone this can be any time of the day or night for you personally.
The question is: Is there some exact location on the planet where this is said to occur?
The answer is: YES! The Summer Solstice occurs at the exact time in the orbit of the earth around the sun when its axis is pointed most directly at the sun. Because the axis of the earth is inclinded to its orbital plane then this will mark the location and time when the sun is at its most northly location and directly overhead at noon. The line of latitude that marks the northern most location of the overhead sun is called the tropic of cancer.
The tropic of cancer is 23o26'22" degrees north. And when it is 0545am GMT which is 0o0'0" longitude it is 1200 (noon) at 64o30'00" longitude East.
Here is the location on a map: