West Virginia Constitution, Article VI
The West Virginia Constitution is unique in providing for an explicit mechanism to convert the state's Senate elections to a proportional voting plan. The pertinent section within Article VI is excerpted below:

6-50.  Plan of proportional representation.

The Legislature may provide for submitting to a vote of the people at the general election to be held in 1876, or at any general election thereafter, a plan or scheme of proportional representation in the Senate of this state; and if a majority of the votes cast at such election be in favor of the plan submitted to them, the Legislature shall, at its session succeeding such election, rearrange the senatorial districts in accordance with the plan so approved by the people.  
Recent Articles
October 19th 2009
A better election system
Lowell Sun

Election expert Doug Amy explains how choice voting can "inject new blood" into the elections of Lowell (MA), and give voters a greater incentive to participate.

October 16th 2009
Haven't Detroit voters spoken enough?
Livingston Daily

In Detroit, there have been three mayors in the past two years and the current one has come under scrutiny. Perhaps a system like instant runoff voting will help bring political stability to motor city.

August 21st 2009
Black candidate for Euclid school board to test new voting system
Cleveland Plain Dealer

Limited voting, a form of proportional voting, will be used in Euclid (OH), in the hopes of allowing better representation of minorities.

July 2nd 2009
Reforming Albany
New York Times

FairVote's Rob Richie responds in a letter to the editor making the case for proportional voting systems to bring substantive reform to New York's legislature.