If you're thinking of volunteering, listen to what I consider the most critical states
Top critical level - tossup states
Ohio (Kerry up by average of 1.0 in recent polls)
Florida (Bush up by average of 0.2 in recent polls)
Iowa (voter registration deadline is Saturday)
Wisconsin(you can register on election day)
New Mexico (almost narrow Kerry)
ME CD 2 (only 1 elector, register election day)
2nd tier - Narrow Kerry states
New Hampshire (register election day)
Maine at large(2 electors, register election day)
Pennsylvania
Minnesota (almost lean Kerry, register election day)
3rd tier - potentially winnable narrow lean Bush states
Nevada
Colorado
Arkansas
Missouri
Iowa and Wisconsin are important. If Kerry wins Ohio but loses those both, he loses.