I recently led an outdoor service for Pentecost and the Church had a presence at the village carnival. I wanted a way of engaging with people so I purchased the A1 size Baptism tree poster, and a set of leaves.
A1 size is the normal size for most flip chart boards that we have around, so it was easy to display it.
I then went back through the Baptism register entering names and date of baptism onto the leaves and placed them on the tree. This was displayed outside the tent and caused some interest with people looking.
It gave me chance to open conversation with those that stopped to look.