Approval voting is an alternate voting system which has many advantages over our standard first-past-the-post system. Instead of marking a single candidate, the voter marks every candidate of which they approve. This eliminates concerns about vote-splitting and spoilers, allowing more open elections with more than two viable candidates. It has the added advantages of being simple to explain, and easy to implement with existing voting machines.
Has any municipality or state in the US ever used approval voting? Have there been any concerted movements in that direction?