Prayer Stones - Assemble a collection of smooth stones and ask participants to choose one and hold it firmly in their hands, focusing on and praying for a particular joy or concern. When ready, worshippers should take a sharpie and write a word on phrase on the stone to represent their prayer and then add it to the growing pile left by others.
Candle Shape Prayers - Set out a number of votive candles and a lighter. Instruct a small group to work together, in silence, to form together a shape or symbol to represent a prayer need of the world. When the group senses the image is complete, have them work together to light each candle, hold hands, and pray in silence.
Pipe Cleaner Prayers - Invite worshippers to take several pipe cleaners and form a shape or design that communicates a prayer concern. Ask them to add their creation to those of others and to spend time contemplating all the prayer concerns represented.
Stick Sculpture Prayers - I must admit the exact focus of this one alludes me but I'm sure you could creatively adapt it. Found sticks were provided and the group worked together to form a sculpture. Perhaps each added stick represents an individual prayer and the sculpture represents our prayers connected to each other, or perhaps the entire sculpture represents a prayer.
Of course, any of these prayer experiences could be enhanced by providing scriptures to read, sacred music, written questions to encourage thought and meditation, or icons such as images of Jesus or biblical stories in art. You can find other creative worship ideas, including more suggestions for interactive prayer stations, here.