Request money for a youth group

As a youth pastor, you'e constantly collecting money from kids and families to cover the cost of the events you plan. You've got that trip to the laser tag course coming up next month, and a canoeing trip after that, not to mention the bowling activity planned for next week. The kids in the group pay with cash or checks, but what you'd really like is a simple way for them to pay without so much paper and manual record-keeping.