I picked up a cheap road tire from Performance. That way I don't have to swap out the tires if I want to go for a ride later.
Easiest thing would be to have a spare wheel, but that's a little unrealistic...
My bike has 26 inch wheels... I will be putting a cheap tire on it when it is time, I am just trying to decide how long I can leave my premium tires on before they get damaged from the trainer...