Gonzales Research & Marketing Strategies Maryland Poll:
Obama 52% (+1 from March)
McCain 38% (+1)
Undecided 10% (-2)
The survey was conducted by Gonzales from Aug. 29 through Sept. 5. Eight hundred thirty-three registered voters in Maryland who indicated they will likely vote in November's general election were interviewed by telephone. The poll has an error margin of plus or minus 3.5 percentage points.
Article about the poll from examiner.com
here. I can't find the actual poll on Gonzales' website (link to March poll
here).
I don't know much about Gonzalez Research & Marketing Strategies, but parts of this poll have been picked up by local media outlets, including the Washington Post and Times.