Here are some early 2012 voting numbers around the country, courtesy of the U.S. Election Project:
Total ballots cast in the United States: 3,571,075
Total ballots cast in Ohio: 502,737. This represents 8.7% of the 2008 total vote in Ohio (which went for Obama).
Total ballots cast in North Carolina: 387,721. Of those, 49.4% were cast by Democrats, 32.2% by Republicans, and 18.3% by none/other.
Total ballots cast in Virginia; 311,420. No partisan id available. But by sex, 55.2% were from females, 44.8% from males.
Florida requested/sent ballots: 1,758,748. Of those, 40.4% were registered Republicans, 40.2% registered Democrats, and 19.5% none/other.