Everyone has been in a situation where you are with a group of people who can't all make up their mind, a decision has to be made and the only fair thing to do it to hold a vote. You can use your dry erase cards as part of the voting system. Each participant in the vote writes they choice on a dry erase card and places it face down in a pile or into a hat / bag ect.
One nominated invigilator who is unbiased to the situation will then look at each card in turn and count the votes. The good thing about using Dry Erase Cards rather than paper or post it notes is that the information on the cards can be quickly and easily erased with no trace. This is important for a closed voting system where the winner but not the amount of votes is announced in order to spare embarrassment or allow other people to guess the direction of votes in a small group. What is written on the cards is eliminated by the invigilator for nobody to see but them.