Fun activities for welcoming new girls?

I need to think of a creative and fun thing to do to welcome new girls into my youth group at church. We all know them, but every two years you move up a group, and I'm in charge of thinking of a way to invite them. Some things that other groups do is "kidnap" them, where they come to your house, put a pillow-case over your head, and drive you to dairy queen where everyone gets ice cream, and heart-attack them, where they come to your house when your mom tells them you're away and stick bajillions of paper hearts (sometimes with hershey's kisses glues on them) all over your room. I really want to do something fun like that! Please help!