One ministry used the example of the Berlin Wall as a sobering way to highlight unreached people group barriers and needs. A display board and portable version were created using cardboard, hinges, brick-looking background and unreached peoples prayer cards.
The displays showed a brick wall background with clear plastic holders stapled to the board to hold the prayer cards. During a service or small group presentation people were challenged to come forward and take a prayer card and pray for 90 days for that people group. Slots were refilled as people took the cards.