Electors in these States are not bound by State Law to cast their vote for a specific candidate:
ARIZONA - 10 Electoral Votes
ARKANSAS - 6 Electoral Votes
DELAWARE - 3 Electoral Votes
GEORGIA - 15 Electoral Votes
IDAHO - 4 Electoral Votes
ILLINOIS - 21 Electoral Votes
INDIANA - 11 Electoral Votes
IOWA - 7 Electoral Votes
KANSAS - 6 Electoral Votes
KENTUCKY - 8 Electoral Votes
LOUISIANA - 9 Electoral Votes
MINNESOTA - 10 Electoral Votes
MISSOURI - 11 Electoral Votes
NEW HAMPSHIRE - 4 Electoral Votes
NEW JERSEY - 15 Electoral Votes
NEW YORK - 31 Electoral Votes
NORTH DAKOTA - 3 Electoral Votes
PENNSYLVANIA - 21 Electoral Votes
RHODE ISLAND - 4 Electoral Votes
SOUTH DAKOTA - 3 Electoral Votes
TENNESSEE - 11 Electoral Votes
TEXAS - 34 Electoral Votes
UTAH - 5 Electoral Votes
WEST VIRGINIA - 5 Electoral Votes
http://www.archives.gov/federal_register/electoral_college/laws.html
http://www.archives.gov/federal_register/electoral_college/2004/index.html
http://www.ncsl.org/programs/legman/elect/ElectoralCollege.htm