Kirsten's phone is a pre-paid T-Mobile. Usually we add $25 in minutes at a time, which I think is 120 minutes. Those do expire after a year I think but usually it's about once every 3 months or so she has to re-up. When my iPhone plan expires I'm going the same route, $100 per year instead of $80 per month makes a lot more sense when I roll over 90% of my minutes per month already.
"Silent enim leges inter arma." -- Cicero