Raise money for a leadership retreat

You're in charge of activity planning for the leadership at your church and the annual retreat is getting closer on the calendar. The hassle of collecting the registration fees is looming. Your fellow leaders meet every week in the midst of busy, busy lives and often can't be counted on to remember to bring cash or a check. You don't want to tax the church budget any more than you have to, so you're looking for a solution that will combine the convenience of online payment with some kind of registration mechanism. So there's no more forgotten money and less work collecting registrations for you.