Here is a simple idea which involves all the Godparents at a baptism.
Ask each Godparent to bring some water to the baptism from a significant place in their lives. Add this water to the water in the font.
Ask each Godparent to write something about the water they have brought and why they chose the place it came from, include some pictures. Give this to the Godchild as a memento of the day. (See Gallery photos)