Leading VP Candidates

Edwards, not for a state but because he adds more conservative voters across the country. Democrats who have been paying attention to this race like Edwards and so do Independents. A Kerry/Edwards ticket swamps Bush/Cheney nationally. Of course, presidential races aren't won nationally.
Gephardt, For the Midwest
Graham or Nelson - For Florida
Clark or Cleland - further pounding Bush with military experience.
Richardson - for the Southwest and Latino vote.
Landrieu, for Louisiana and ticket balance, you can't get more balanced than a conservative, Southern female.
If there was a strong, prominent Ohio Democrat Kerry would grab him in a minute. Kucinich doesn't count.